
Model	Dates		Front Scales	Rear and Other Calculating Scales	Body	Comment	Also Sold As
Models1-18: Obsolete Model Numbers Abandoned About 1930.
1 1/1	1913-29	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 250 x 28 x 9.5 mm	Mannheim. ("Normal") Listed as obsolete starting in 1936 but price listed in Hemmi catalogs through 1937 and available from Frederick Post (as model 1449) through 1940.	Tamaya 1941 (1916-27); H-O 1768 (-1914-); Post 1449 (1930-WWII)
	Pic	Artillery variant with minutes and mils conversion scales on bottom edge and trigonometric formulas for gunnery on back of rule. Dates probably later than model 1.
	Pic	A [B, Stadia, C] D	Stadia variant. Stadia scale (SinCos and Cos²) added to front of slide. Dates probably later than model 1.
2	1913-29	Pic	Same as model 1 but with decimal-indicating cursor.	//Closed\|\| 250 x 28 x 9.5 mm	Discontinued ca1929.	Tamaya 1937 (1913-27); H-O 1767 (-1914-28-)
3	1919-29	Pic	LL2, A [B, C] D, LL3	[S, L, T] Gutter: E, F	//Closed\|\| 250 mm x 1½ in x 10 mm	Electro. (Copy of Faber 378) LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No over-range. HP gauge mark (probably only 746). Single hairline. At least three different cursors. Tamaya 1905 (1919-27); H-O 1770 (1928), Hemmi 80 (1930+).
4	1919-29	Pic	Same as 3 but with decimal-indicating cursor.		Tamaya 1904 (1916-27), Hemmi 81 (1930+
5	1919-29	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 500 mm x 1¼ x 13/32 in	Listed as obsolete by Hemmi in 1936 but price listed through 1937. In Post catalog (model 1450) until WWII and in H-O catalog (model 1772) though1948.	Tamaya 1899 (1916-27); H-O 1772 (1928); Post 1450 (1936-WWII).
6	1919-29	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 125 x 24 x 9 mm	Pocket Mannheim. Replaced by model 48 ca1930.	H-O 1763 (-1914-35); Tamaya 1942 (1916-27).
7	1926-29	Pic	Same as 6 but with decimal-indicating cursor		Tamaya 1949 (1927)
8	1913-29	Pic	A [B, C] D	[S, L, T]	/Closed\|\| 125 x 24 x 9 mm	Extra Fine Mannheim w Magnifier.	Tamaya 1943 (1916-27); H-O 1764 (-1914-48-)
9	1919-29	Pic	Same as 8 but with magnifiying decimal-indicating cursor	Discontinued ca1929.	Tamaya 1900 (1916-27)
10	1926-29	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 250 mm	Ten-inch extra fine with "extended lens" magnifier. Discontinued ca1929.	Tamaya 2148 (1927)
11	1926-29	Pic	Same as10 but with decimal-indicating "extended-lens" cursor.	Discontinued ca1930.	Tamaya 2180 (1927)
12		NA	DF [CF, CI, C] D (Folded at ?)	Blank	? 150 mm	Simplified Slide Rule. Plastic. Single uncorroborated reference.
12	1926-29	Pic	Same as model 3 but with "extended-lens" magnifying cursor.	Discontinued ca1929.	Tamaya 2782 (1927)
13	1926-29	Pic	Same as 4 but with decimal-indicating "extended-lens" cursor.	Discontinued ca1929.	Tamaya 2783 (1927)
14	1926-29	Pic	A [B, C] D	[S, L, T]	\|\|Closed\|\| 100 mm x 11/16 x 7/32 in	Vest Pocket Mannheim with square edges.	Tamaya 2784 (1927); Hemmi 35 (1930+)
15	1926-29	Pic	Same as 14 but with decimal-indicating cursor.	Discontinued ca1929.	Tamaya 2785 (1927)
16	1926-29	Pic	Same as 14 but with magnifying cursor.	Discontinued ca1929.	Tamaya 2786. Hemmi 35ML (1930+)
17	1926-29	Pic	Same as 14 but with magnifying decimal-indicating cursor.	Discontinued ca1929.	Tamaya 2787
18	1826-29		Pocket kit including pen, pad and model 15 slide rule.	Discontinued ca1929.	Tamaya 2788
19	1927	Pic	A [B, C] D	[S, L, T] ?	250 mm	Student version of model 1. Model number may have been changed to 40 before any were actually sold.
Model Numbers 20-24 were assigned to Classroom Demo Slide Rules before WWII; Student Rules after WWII.
20	1932-42	NA	A [B, CI, C] D, K	[S, L, T]	Demo 2000 mm	Demonstration Mannheim (Model 50)	Tamaya 4451 (1932)
21	1932-42	NA	K, A [B, CI, C] D, L with over-range	[S, S&T, T]	Demo 2000 mm	Demonstration Rietz (Model 64).	Tamaya 4452 (1932)
22	1951-59	Pic	[CI, C] D, A	No back	Special 200 x 23 x 9 mm	Cheap student rule distributed in Asia only. Slide held to single stator. Some (1955 only?) sandalwood, not bamboo. Celluloid cursor.
P23	1957-69	Pic	A [B, CI, C] D	A [B, CI, C] D	Open 180 mm x 1 x 1/8 in	Student Mannheim w CI scale. Hemmi's first plastic-based rule.
24	1927	Pic	A [B, C] D	Blank	//Closed\|\| 125 x 26 x 3 mm	Ultra-thin all plastic with celluloid cursor. 13 cm scale on top edge; bottom blank. Identical to model 34 except imprinted with advertising. Rare. Appears in no known catalog.
P24	1963-69	Pic	DF [CF, CI, C] D, A Folded at √10.	Blank	Open 180 mm x 1 x 1/8 in	Student.
Models 30-39: Miscellaneous Four- and Five-inch Closed Body Slide Rules
30	1930-43	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 100 mm x 11/16 x 7/32 in	Vest Pocket Mannheim. Model number never appears on rule. Some w "SUN" cut through or "SKF" embossed into backing plate. 1000¥ ($2.78) in 1969.	Tamaya 4453 (1927); Post 1447 (1931-33); Post 1440 (1934-WWII)
31	1930-42	Pic	Same as 30 but with decimal-indicating cursor.	No CI scale	Tamaya 4454
32	1930-42	Pic	Same as 30 but with magnifying cursor.	Tamaya 4455; Post 1447M (1931-33); 1441 (1934-WWII); Boston Blue Print 1441; US Blue 1888.
33	1930-42	Pic	Same as 30 but with decimal-indicating magnifying cursor	No CI scale	Tamaya 4456
30R	MIOJ-1950	Pic	A [B, CI, C] D	[S, L, T] (S keyed to A/B except WWII-1955 keyed to C/D)	//Closed\|\| 100 mm x 11/16 x 7/32 in	Vest Pocket Mannheim w CI scale. No model number on rule but case and box marked "30R."	Fuji 41. Post 1440.
30	1951-EOB	Pic	Same rule with "R" dropped from model number on case and box. All-plastic cursor after ca 1970.
32R	MIOJ-1950	Pic	Same as 30R but with magnifying cursor	Post 1441(WWII-1971); T-P 44DA-410 (1972+); H-O 1760 (-1952-64); Geo 341-3405 (1964+) US Blue 1888 (MIOJ)
32	1951-EOB	Pic	Same as 30 but with magnifying cursor.
P33S	1971	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to C/D)	Closed 125 x 28 x 5 mm	Pocket Improved Mannheim. All-plastic version of model 34RK.
P33/SS	1970	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to C/D)	Closed 125 x 27 x 4.5 mm	Pocket Improved Mannheim. Unique size.	Geotec 341-3610
34	1932	Pic	A [B, C] D	Blank	//Closed\|\| 125 x 26 x 3 mm	Ultra-thin all plastic with celluloid cursor. 13 cm scale on top edge; bottom blank	Hemmi 24; Tamaya 4457
34P	1932-42	NA	A [B, C] D	Blank	//Closed\|\| 125 mm x 15/16 x 5/32 in	Thin Pocket Mannheim with blank back.	Post 1443 (1931-WWII)
MIOJ	Pic	//Closed\|\| 125 x 26 x 5 mm
34π	1932-42	Pic	CF [DF, CI, C] D Folded at π	[S, L, T] (S keyed to C/D)	//Closed\|\| 125 mm x 15/16 x 5/32 in	Thin Pocket Mannheim with folded scale.	Post 1444 (c1935-WWII); H-O 1762 (-1935-WWII)
MIOJ	NA	//Closed\|\| 125 x 26 x 5 mm
34R	1935-40	Pic	A [B, CI, C] D	[S, L, T] (S keyed to A/B except WWII-1955 keyed to C/D)	//Closed\|\| 125 mm x 15/16 x 1/8 in	Thin Pocket Mannheim w CI Scale.	Post 1444 (c1935-WWII); H-O 1762 (-1935-WWII)
1955-68	NA	//Closed\|\| 125 x 26 x 5 mm
34RK	1936-EOB	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to A/B except WWII-1955 keyed to C/D)	//Closed\|\| 125 x 26 x 5 mm	Post 1444K (1937-70),1444(1971); T-P 44DA-440 (1972+); US Blue 1887 (1930s); H-O 1762 (WWII-64); Geo 341-3425 (1964+).
34T	1936-42	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 125 mm x 15/16 x 1/8 in	Thin Pocket Mannheim. "SUN" or ASEA embossed into backing plate.
35	1935-48	Pic	A [B, C] D	[S, L, T]	\|\|Closed\|\| 100 mm x 11/16 x 3/16 in	Vest Pocket Mannheim with 4-inch and 10-cm measuring scales on square edges	Hemmi 14; Post 1437 (c1935-WWII); H-O 1761 (-1935-48-)
35ML	1930s	Pic	Same as 35 but with magnifying cursor	Hemmi 16
P35 B35	1959-61	Pic	K, DF [CF, CI, C] D, A Folded at √10.	Blank	Open 115 mm x 1 x 1/8 in	Marked "B35" (factory error for "P35"?); thin bamboo core covered with PVC (not celluloid); scales printed (not engraved). All known specimens also marked H-O 1759.
P35S	1971	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[LL1, LL2, LL3]	Closed 125 x 28 x 4.6 mm
36	1936-WWII	Pic	A [B, CI, C] D	[S, L, T]	Closed 125 mm x ¾ x 7/32 in	Narrow Pocket Mannheim w CI scale. Measuring scales on BACK of rule.	Post 1438 (c1935-WWII)
P36 P36S	1966-70	Pic	D [Conversion gauge marks, A] D	Instructions [Conversion gauge marks, B] Instructions	Open 115 mm x 1 x 1/8 in	Rule is labeled "P36;" box and instructions "P36S." Set arrow on slide opposite value on top D scale; converted value appears on bottom D scale opposite corresponding arrow. Reverse slide for more conversions. Markings and instructions in Japanese. 450¥ ($1.25) in 1969.
P37	1966-70	Pic	(1), (2), D [C, CI, B] MD1, MD2	[B, PR1, PR2, PR3]	Closed 125 x 28 x 4.6 mm	SALES. Labeled in Japanese. MD1 is months and days from 1/1 to 6/30, MD2 from 7/1 to 12/31. PR1-2-3 = three short profit ratio scales. Reverse slide to read B, PR scales.. {Two hairlines: D: 1.2}. 700¥ ($1.94) 1969.
P39		NA	K, A, DF [CF, CIF, CI, C] D, DI, L Folded at ?	[B, TI, SI, C]	Closed 125 mm	Single uncorroborated reference.
Models 40-49: Basic Mannheim Rules (A [B, C] D) before WWI and "Improved" Mannheim (A [B, CI, C] D, K) after WWII.
40	1932-49	Pic	A [B, C] D	[S, L, T]	Closed 250 x 28 x 8 mm	Tamaya 4458 (1927), Post 1446 (1931-49); H-O 1768 (-1935-48-); Boston Blue Print 1446; US Blue 1876 (1930s); Lietz 2974N (1930s).
41	1932-42	Pic	A [B, C] D	[S, L, T]	Closed 125 mm	Pocket Mannheim. No measuring scales	Tamaya 4459 (1932)
42	1932	Pic	A [B, C] D	[S, L, T]	Closed 250 x 28 x 8 mm	Model 40 w measuring scales on BACK.	Tamaya 4460 (1932)
43	1932	NA	Same as 42 but with decimal-indicating cursor.	Tamaya 4461 (1932)
44	1932	Pic	A [B, C] D	[S, L, T]	Closed 125 mm x 15/16 x ¼ in	No slant; cm & inch scales on back of rule.	Tamaya 4462 (1932)
45	1932	NA	Same as 44 but with decimal-indicating cursor.	Tamaya 4463 (1932)
45	1949-68	Pic	DF [CF, CI, C] D, A Folded at √10.	[TI, L, SI]	Closed 200 x 28 x 8 mm	Student. Quite different from 1932 model 45.
46	1936-42	Pic	A [B, C] D	Blank	Special. 125 mm x 1 in	"Cardboard covered in transparent celluloid with leather sheath."
47	1936-42	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 250 x 28 x 8 mm	Thin successor to model 1/1.	Post 1449T (1937-WWII)
48	1932-42	Pic	A [B, C] D	[S, L, T]	//Closed\|\| 125 mm x 15/16 x ¼ in	Pocket Mannheim. Thin successor to model 6.
40F	1968-69	Pic	K, DF [CF, CI, C] D, A Folded at √10	[TI, L, SI]	Closed 250 x 28 x 8 mm		Fuji 85.
40RK	1949-69	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to A/B except Staedtler 944-55 keyed to C/D)	Closed 250 x 28 x 8 mm	Improved Mannheim. ("Slide Rule with CI and K Scale" in early literature)	Post 1447 (c1949-1971); H-O 1768C (-1952-64); Geo 341-3526 (1964-71); US Blue 1877 (1940s?).
1973	Pic	Same as preceding but wider with thick plastic back.	Closed 250 mm x 1¼ x 9/32 in	T-P 44BA-470 (1972+); H-O 341-3526 (1972+)
40-50		Pic	Overhead projection rule for Hemmi model 40RK.	Projection 305 x 182 x 12 mm
P 40RK	1967-69	Pic	A [B, CI, C] D, K	[S, L, T]	Open 250 x 28 x 8 mm	All-Plastic Improved Mannheim. Hard plastic case.	Post 1447P (c1967); Geo 341-3530 (c1967)
43A	1961-71	Pic	A [B, CI, C] D, K	[T, L, S] (S keyed to C/D)	Closed 200 x 28 x 8 mm	Student Improved Mannheim.
P43D	1973-EOB	Pic	A [B, CI, C] D, K	[T, L, S] (S keyed to C/D)	Closed 200 x 28 x 6.4 mm	Like 43S except no indices on back of rule; slide must be reversed.
P43S	1969	Pic	A [B, CI, C] D, K	[T, L, S] (S keyed to C/D)	Closed 200 x 28 x 6.4 mm	Plastic version of 43A. Indices for reading trig scales on back of rule.
45K	1962-EOB	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[TI, L, SI]	Closed 200 x 28 x 8 mm	Post 1445 (c1966-71); T-P 44BA-450 (1972+); Geo 341-3500 (1967+). All have scales folded at π.
P45K	1965-69	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[TI, L, SI]	Open 200 x 28 x 5 mm	Open body all-plastic version of 45K	Post 1445P (-1965-) Scales folded at π.
P45D	1973-EOB	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[T, L, S]	Closed 200 x 28 x 6.4 mm	"Junior High School Students." Like P45S except trig scales not inverted and no indices on back of rule; slide must be reversed.
P45S	1969-73	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[TI, L, SI]	Closed 200 x 28 x 6.4 mm	Closed body all-plastic version of 45K. Simpler construction than P45K.
Models 50-59: "Improved" Mannheim Slide Rules (A [B, CI, C] D, K and [S, L, T]) and Variants.
50, 50/1, 50/3	1932-51	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to A/B except WWII-1955 keyed to C/D)	//Closed\|\| 250 x 28 x 10.5 mm	Improved Mannheim. Formerly model 102.	Hemmi 102; Tamaya 4464 (1932); Post 1452 (c1935-51); H-O 1771 (-1928-48-); US Blue 1880 (1930s).
50F, 50/1F	1936-MIOJ	Pic	A [B, CI, C] D, K	[S, L, T]	//Closed\|\| 250 x 28 x 8 mm	Thin version of 50, 50/1 but accepts standard cursor.	Post 1452T (1936-WWII).
50π/1	1936-42	Pic	A, DF [CF, CI, C] D, L Folded at π.	[S, S&T, T]	//Closed\|\| 250 x 28 x 10.5 mm		Post 1455 (c1935-WWII).
50W	1951-EOB (For Post)	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to A/B except WWII-1955 keyed to C/D)	//Closed\|\| 250 x 34 x 11 mm	Wide Improved Mannheim.	Post 1452W ('51-70), 1452 ('71); T-P 44BA-520 ('72+); H-O 1771 ('51-64); Geo 341-3215 ('64+).
P50	1965?-68?	NA	A [B, CI, C] D, K	Blank	Open? 250 mm x 1½ in	Improved Mannheim.
50-20	1935-48	Pic	A [B, CI, C] D, K	[S, L, T]	//Closed\|\| 500 x 34 x 11 mm	Long Improved Mannheim. Made for Post & H-O only; not sold as Hemmi brand.	Post 1454 (-1936-WWII); H-O 1772 (-1935-58-) H-O 341-3235 (-1969-).
WWII-1969	Pic	//Closed\|\| 500 x 40 x 12 mm	Wide Long Improved Mannheim. Hemmi & Post brands. {Three Hairlines: D: C, C}.
51/1, 51/3	1932-42	Pic	Same as 50/1, 50/3 but with decimal-indicating cursor.	Formerly model 103.	Tamaya 4466, 4467 (1932).
52	1932-42	Pic	A [B, CI, C] D	[S, L, T]	//Closed\|\| 125 mm x 15/16 x 11/32 in	Thicker than 34R.	Tamaya 4468; Post 1448 (1936-37).
53	1932-42	Pic	Same as 52 but with decimal-indicating cursor.	Tamaya 4469 (1932).
54	1936-42	Pic	A [B, CI, C] D, K with over-range	[S, L, T]	//Closed\|\| 150 x 26 x 6 mm	"Extra Fine Improved Mannheim" with magnifying cursor.	Post 1453 (c1935-WWII).
55	1936-42	NA	Same as 54 but without magnifying cursor.
Models 60-79: Rietz Slide Rules ( K, A [B, C] D, L and [S, S&T, T] )
60/1, 60/3	1932-3x	Pic	K, A [B, C] D, L	[S, S&T, T]	//Closed\|\| 250 mm x 1¼ x 13/32 in	Rietz. Single line model 60/1 discontinued ca 1930.	Tamaya 4470, 4471 (1932)
193x-42	Pic	K, A [B, C] D, L with over-range
61/3	1932-42	NA	Same as 60/3 but with decimal-indicating cursor.
62/3	1932	NA	K, A [B, C] D, L	[S, S&T, T]	//Closed\|\| 150 mm	Extra Fine Rietz.	Tamaya 4472, 4473 (1932)
63/3	1932	NA	Same as 62/3 but with decimal-indicating cursor.
64, 64/1, 64/3	1932-68	Pic	K, A [B, CI, C] D, L with over-range	[S, S&T, T]	//Closed\|\| 250 x 34 x 11 mm	"System Rietz." {64/3 hairlines: D: C, C} Some w 13-0-13 cm on bottom. Probably without over-range before 1935.	Tamaya 4474 (1932)
64T	1965-71	Pic	K, A [B, BI, CI, C] D, DI, L with over-range	[T2, T1, ST, S]	//Closed\|\| 250 x 34 x 11 mm	"Super Rietz." {3 hairlines: D: C, C}.
65	1932-42	Pic	Same as 64/3 but with decimal-indicating cursor.	//Closed\|\| 250 x 34 x 11 mm		Tamaya 4475 (1932)
66	1932-68	Pic	K, A [B, CI, C] D, L with over-range	[S, S&T, T]	//Closed\|\| 150 x 26 x 9 mm	Extra Fine Improved Rietz. {3-line cursor: D: C, C} Some 8-0-8 cm on bottom.	Tamaya 4476 (1932)
66F	1936-42	Pic	Same as 66 but thin.
67	1932-42	NA	Same as 66 but with 3-line magnifying cursor.		Tamaya 4477 (1932)
68	1932-42	NA	Same as 66 but with 3-line decimal-indicating cursor.		Tamaya 4478 (1932)
69	1932-42	NA	Same as 66 but with 3-line decimal-indicating magnifying cursor.		Tamaya 4479 (1932)
70	1932-43	Pic	K, A [B, CI, C] D, L some with over-range	[S, S&T, T]	//Closed\|\| 500 x 34 x 12 mm	Long Improved Rietz. {3 hairlines: D: C, C}.	Tamaya 4480 (1932)
1951-70	Pic	//Closed\|\| 500 x 40 x 12 mm
72	1966-71	Pic	K, DF [CF, CIF, CI, C] D, A with over-range Folded at √10.	[TI2, TI1, L, SI]	//Closed\|\| 500 x 40 x _ mm	"Precision Slide Rule for Practical Engineers." Single hairline.
74	1937-EOB	Pic	K. A [B. CI. C] D, L with over-range	[S, S&T, T]	//Closed\|\| 125 x 26 x 5 mm	Pocket Improved Rietz. {3 hairlines: D: C, C}.
Models 80-89: "Electro" Slide Rules
80 80/1 80/3	1930-32	Pic	LL2, A [B, CI, C] D, LL3 No over-range	No over-range [S, L, T] E, F widely separated in gutter.	//Closed\|\| 250 mm x 1 ¼ in x 10 mm	Electro. LL scales keyed to offset "W" gauge mark. No over-range. Same as model 3 with CI scale added.	Hemmi 3; Tamaya 4481, 4482 (1932); H-O 1770 (-1928-c50); Post 1456 (c1934-WWII)
1932-33	Pic	//Closed\|\| 250 x 34 x 11 mm	Same as preceding but on slightly wider body.
1934-36	Pic	[S, L, T] E, F close together in gutter	Same as preceding but no "W" gauge mark. E, F close together in gutter.
1936-52	Pic	LL2, A [B, CI, C] D, LL3 with over-range	Same as preceding but with over-range extensions.
81/1, 81/3	1932-42	Pic	Same as 80/1, 80/3 but with decimal-indicating cursor.	Details vary depending upon date of manufacture. See model 80.	Hemmi 4; Tamaya 4482, 4484 (1932)
82	1932-37	NA	Same as 80/1 except short.	//Closed\|\| 125 x _ x 9 mm		Tamaya 4485 (1932)
83	1932-37	NA	Same as 82 but with decimal-indicating cursor.	Tamaya 4486 (1932)
84	1932	NA	Same as 82 but with magnifying cursor.	Tamaya 4487 (1932)
85	1932	Pic	Same as 82 but with magnifying decimal-indicating cursor.	Tamaya 4488 (1932)
85	MIOJ	Pic	db, Neper, A [B, CI, C] D	[TI2, TI1, L, SI1]	//Closed\|\| 250 x 34 x 11 mm	Not electro, therefore model number 85 is inappropriate. {3 hairlines: A: C², 1.307} (Why 1.307?)	Rare.
80K	1953-70	Pic	E, F, A [B, CI, C] D, LL2, LL3 with over-range	[S, L, T] Bottom Edge: K	//Closed\|\| 250 x 34 x 11 mm	Electro. K scale on bottom edge; no scales in gutter. No hp mark but different cursors avail for British/US and French/Metric HP. {3-line cursor: A: hp, C²}.
86/3	1936-42	NA	LL2, A [B, CI, C] D, LL3 with over-range	[S, L, T] Gutter: E, F	//Closed\|\| 150 x 26 x 8 mm	"Extra fine Electro." Hp gauge mark. No W mark. E,F scales close together in gutter. {Three hairlines: A: hp, C²}.
87/3	1936-42	NA	Same as 86/3 but with magnifying cursor.
86/3K	1950	Pic	LL2, A [B, CI, C] D, LL3 with over-range	[S, L, T] Gutter: E, F Bottom Edge: K	//Closed\|\| 150 x 26 x 8 mm	Same as model 86/3 except K scale added to bottom edge.
86	1951	Identical to and contemporaneous with model 86/3K.
86K	1954-70	Pic	E, F, A [B, CI, C] D, LL2, LL3 with over-range	[S, L, T] Bottom Edge: K	//Closed\|\| 150 x 26 x 8 mm	"Extra Fine Electro." No scales in gutter, no hp mark. {Three hairlines: A: hp, C²}.
Models 90-99: Stadia Slide Rules
90	1932-42	Pic	L, D [M1, M2, C] D, A with over-range	[S, S&T, T] Bottom Edge: K, IA	//Closed\|\| 250 x 34 x _ mm	Stadia. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to rightmost hairline.
90A	1940	NA	Same as 90
90B	1939?	Pic	Same as 90 but uses "centesimal degrees." (100 centesimal degrees = right angle)	First of a proposed series (models 90B, 91B, 2690B) of centesimal-degree stadia rules. Models 91B and 2690B were never manufactured.
91	1932-42	Pic	Same as 90 but with decimal-indicating cursor		Tamaya 4490 (1932)
91A	1939?	NA	Same as 91.	"91A" used to distinguish this rule from proposed centesimal degree model 91B.
92	1932-42	Pic	L, D [M1, M2, C] D, A	[S, S&T, T] Bottom Edge: K, IA	//Closed\|\| 150 x 26 x 9.6 mm	"Extra Fine Stadia." Two calculating scales on bottom edge. {3 hairlines: D: C, C}.	Tamaya 4491 (1932)
93	1932-42	Pic	Same as 92 but with magnifying cursor.	Tamaya 4491 (1932)
94	1932-42	NA	Same as 92 but with decimal-indicating cursor.	Tamaya 4491 (1932)
95	1932-42	NA	Same as 92 but with decimal-indicating magnifying cursor	Tamaya 4491 (1932)
96	1936-43	Pic	L, D [M1, M2, C] D, A with over-range.	[S, S&T, T] Bottom Edge: K, IA	//Closed\|\| 500 x 34 x 11 mm	Long version of model 90. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to center hairline.
Model Numbers 100-107 were assigned to new rules developed in 1926-27; all were replaced by modern numbering system about 1930.
100	1926-27	Pic	A [B, CI, C] D	[S, L, T]	//Closed\|\| 250 mm	Short lived.	Tamaya 2790 (1927)
101	1926-27	Pic	Same as 100 but with decimal indicating cursor.	Tamaya 2791 (1927)
102	1926-28	Pic	A [B, CI, C] D, K	[S, L, T]	//Closed\|\| 250 x 28 mm	Improved Mannheim. Model number changed to 50/1 ca 1928.	Tamaya 2792 (1927), H-O-1771
103	1926-28	Pic	Same as 102 but with decimal-indicating cursor.	Model number changed to 51/1 ca 1928.	Tamaya 2793, (1927)
104	1927	Pic	LL2, A [B, CI, C] D, LL3 No over-range	[S, L, T] Gutter: E, F	//Closed\|\| 125 mm	"Pocket Electro." LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No over-range. Hp gauge mark.	Hemmi 82; Tamaya 2994 (1927)
105	1927	Pic	Same as 104 but with decimal-indicating cursor.	Hemmi 83, Tamaya 2995
106	1927	NA	Same as 104 but with magnifying cursor.	Hemmi 84, Tamaya 2996
107	1927	NA	Same as 104 but with magnifying decimal-indicating cursor.	Hemmi 85, Tamaya 2997
Models 100-109: Large Classroom Demonstration Slide Rules
100	1951-68	Pic	DF [CF, CI, C] D, A Folded at √10.	[TI, L, SI]	Demo 1000 mm	Demonstration version of model 45.
100K	1969-71	Pic	K, DF [CF,CI, C] D, A Folded at √10	[TI, L, SI]	Demo 1000 mm	Demonstration version of model 45K
101	1951-68	NA	ℓ, A [B, CI, C] D	[S, K, T] (S keyed to C/D)	Demo 1000 mm	Demonstration version of model 2640.
101A	1967-EOB	Pic	A [B, CI, C] D, K	[S, L, T] (S keyed to C/D)	Demo 1000 mm	Demonstration version of models 40RK & 43A.
102	1954-68	Pic	CI, C, [D, A]	Blank	Demo 1000 mm	Demonstration version of model 22.
103	1959-EOB	NA	K, DF [CF, CIF, CI, C] D, A Folded at √10.	[TI1, TI2, L, SI]	Demo 1500 mm	Demonstration version of model 2664S.
104	1959-69	NA			Demo 1000 mm	Demonstration.
107	1969-EOB	NA	LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.	K, A [B, TI1, TI2, SI] D, DI	Demo 1000 mm	Demonstration version of model P253.
108	1971?	NA	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10	K, A [B, TI, SI, C] D, DI, L	Demo 1000 mm	Demonstration version of model 254W.
Models 110-129: Specialty Slide Rules
110	1937-MIOJ	Pic	LL2, A [B, CI, C] D, LL3 with over-range	[S, S&T, T] Bottom Edge: K	//Closed\|\| 250 x 34 x 11 mm	Mechanical /Electrical slide rule. K scale on bottom edge. {Three hairlines: D: C, C}.
120	1939?	Pic	L, K, A [B, CI, S₁, T₁, C] D, S_Θ with over-range	[LL3, LL3, LL2, LL2, LL1, LL1] Bottom Edge: G_Θ (2 scales)	//Closed\|\| 250 x 34 x 11 mm	"MIGHT." Listed without description by Katsunori Kadokura (Chronology of Japanese Hemmi Slide Rules, Journal of the Oughtred Soc, Vol 1, No 2, August 1992). Pictured specimen identified as Model 120 by Yukio Kubota, March 2014.
DP121	1968-69	Pic	LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1	K, A [B, TI₂, TI₁, SI] D, DI	Projection 305 x 182 x 12 mm	Overhead projection rule for model P253. Sold with five masks for obscuring irrelevant scales.	¥10,000 in catalog dated 6911
DP122	1968-69	Pic	K, A, DF [CF, CIF, CI] D, DI, L	K, A, DF [B, TI₂, TI₁, SI, C] D, DI, L	Projection 305 x 182 x 12 mm	Overhead projection rule for models 2662 and 2664S. Sold with five masks for obscuring irrelevant scales.
Models 130-139: Darmstadt Slide Rules (L, K, A [B, CI, C] D, Cos, Sin, Tg and [LL1, LL2, LL3]) and Variants
130	1950-69	Pic	L, K, A [B, CI, C] D, Cos with over-range	[LL1, LL2, LL3] Bottom Edge: SIN, tg	//Closed\|\| 250 x 34 x 11 mm	Darmstadt. S and T scales on bottom edge of rule. {3 hairlines: D: hp-C, C}.
130W	1970-72	Pic	T, K, A [B, BI, CI, C] D, P, S with over-range	[L, LL0, LL1, LL2, LL3]	//Closed\|\| 250 mm x 1½ x 7/16 in	Advanced Darmstadt. Unique width. {3 hairlines: A: C², hp-C²}.
135	1959-71	Pic	T, K, A [B, CI, C] D, P, S with over-range	[L, LL1, LL2, LL3]	//Closed\|\| 125 x 26 x 5 mm	Pocket Darmstadt. {3 hairlines: D: hp-C, C}.
P135k	2005	Pic	T, K, A [B, CI, C] D, P, S with over-range	[L, LL1, LL2, LL3]	Closed 200 x 32 x 4.3mm	Darmstadt. Only 250 made. Manufactured by HEMMI in 2005 to specifications of ISRG and Japanese collectors and sold by subscription.
136	1951-68	Pic	L, K, A [B, CI, C] D Cos with over-range	LL1, LL2, LL3] Bottom Edge: SIN, tg	//Closed\|\| 150 x 26 x 8 mm	Extra Fine Darmstadt. D scale is labeled "SIN" other scales not labeled.
Models 140-149: Pocket Duplex Slide Rules
140	MIOJ	Pic	DF [CF, CI, C] D, L Folded at √10.	K, A [B, TI, SI, C] D, DI	Duplex 150 mm x 1 3/16 x ¼ in	Hemmi's first "pocket" duplex. Body is short version of old narrow model 150.
141 P141	1960-EOB	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π	T, S, U, P [Q, c, V, R] A q, n, L	Duplex 125 x 34 x 4 mm	Air conditioning duct design. Bamboo (141) and all-plastic (P141) versions. Same blank as 149. All-plastic version marked "'Carrier' Ductuler" (Toyo Carrier Corp). Some bamboo specimens carry no brand name, some marked "Carrier 50210," others marked "Shin Nippon Kucho." (SNK was spun off from Toyo Carrier in 1969.)
143	1968-69	Pic	P₁, P₂, DF [CF, CIF, CI, C] D, LL (2 scales) Folded at 360.	A, N [M, £, S/d, C] D, G	Duplex 125 x 34 x 4 mm	"Commerce." N, M have 365 division for dates. £, S/d = pound/ shilling/ pence. G is a set of conversion gauge marks.	Pocket version of model P263.
149	1959-1962	Pic	LL/1. LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	L, K, A [B, TI, SI, C] D, LL0, LL/0	Duplex 125 x 34 x 4 mm	"Pocket 259D" but actually closer to 259 with TI, SI instead of T, S, ST. Hemmi name on back of rule. Bare bamboo edges.
149A	1962-EOB	Pic	Same as 149 except celluloid veneer covers edges.
P149A	1976	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	L, K, A [B, TI, SI, C] D, LL0, LL/0	Duplex 125 x 36 x 4 mm	All plastic. About 10 mm longer overall and 2 mm wider than bamboo 149A.
Models 150-300: Ten- and Twenty-Inch Duplex and Open Body Slide Rules
150	1925?-1932?	Pic	DF [CF, CIF, C] D Folded at π.	K, A [B, S, T, CI] D, L	Duplex 250 mm x 1 3/16 x ¼ in	Hemmi's first duplex slide rule. (But Hemmi called models 150, 152, 153 and 154 "Universal," not "duplex.") Copied from K&E 4088-3 whose size it exactly duplicates.	Post 1458 (1931) Lietz 3054L (before 1932)
1932?-MIOJ	Pic	Duplex 250 mm x 1 5/8 x ¼ in	Standard (1-5/8 inch) width. Replaced by model 250.	Tamaya 4497 (1932) Post 1458 (1932-WWII) US Blue 1881 (--1937--) H O 1765 (1935-MIOJ)
152	1925-48	Pic	K, A [B, CI, C] D, T	Θ, R_θ, P [Q, Q', C] LL3, LL2, LL1	Duplex 250 mm x 1 5/8 x ¼ in	"Electrical Engineer's Universal" (Duplex). Often no model number. Some marked "US Pat 1459857." (Patent issued to O D Parsons in 1923 for P, Q scales.)	Tamaya 4498 (1932); Post 1459 (c1933-WWII); H-O 1766 (-1935-48-); US Blue 1889 (1930s) Lietz (1930s)
153	1931-EOB	Pic	L, K, A [B, CI, C] D, T, G_θ	Θ, R_θ, P, [Q, Q', C] LL3, LL2, LL1	Duplex 250 mm x 1 5/8 x ¼ in	"Electrical Engineer's Universal" (Duplex). Some (c1938) with stator screws on back of rule. US Patent 2079464, May 4, 1937.	Post 1461 (c1933-WWII); US Blue 1893 (1030s)
154	1925-69	Pic	DF, P', P [Q, CF, CI, S_θ^o] A, D, K Folded at π.	Sχ, Tχ, T_θ^o [Th, Sh, Sh, C] D, L, χ	Duplex 500 mm x 1¾ x ¼ in	Electrical Engineer's Universal (Duplex) 20". Two cursors. Early production has scale letters eteched on cursor windows.	Tamaya 4499 (1932); Post 1460 (c1933-WWII)
155	WWII-1951	Pic	K, A, DF [CF, B, CI, C] D, L Folded at √10.	Sh₁, Sh₂, Th₁ [TI₂, TI₁, SI₁, C] D, DI	Duplex 250 mm x 1 5/8 x ¼ in	"General Engineering with Hyperbolic Scales. " Replaced by model 255.
157	WWII-1950	Pic	K, A, DF [CF, B, CI, C] D, L Folded at √10.	LL/1, LL/2, LL/3 [TI₂, TI₁, SI₁, C] LL3, LL2, LL1	Duplex 250 mm x 1 5/8 x ¼ in	"General Engineering with Log-Log Scales."
159	1949-52	Pic	T, DF [CF, CIF, CI, C] D, S, ST Folded at π	LL0, LL00, A [B, K, L, C] LL3, LL2, LL1	Duplex 250 mm x 1 5/8 x ¼ in	Made to specification of F Post Co. Replaced by model 259 ("Expert Mechanical Engineer") c1952.	Post 1462H "POSTRIG" (c1949 - 53)
160	1951	Pic	Nomogram1(α=0.05), χ2, A [B, CI, C] D, φ, ax	P, F'1 [F'2, a'] A, χ2, ,Nomogram2(α=0.01)	Duplex 250 mm x 72.5 mm	"Inductive Statistics." Almost three inches wide! Stator with nomograms is about 46 mm wide. All-plastic cursor similar to Relay/Ricoh.
165	1953	Pic				"Statistical Sampling." No slide, just many short scales and a cursor.
190	1939-42	Pic	K, A [B, R2, R1, C] D, DI	[SI2, SCI2, SI1, SCI1] Bottom Edge: L	Closed 250 x 40 x 11 mm	"Precision Stadia." {3 hairlines: D: C, C}. Left half of SCI1 scale is inverse cos².
200	1936-68	Pic	D6, D5, D4 [C6, C5, C4, C3, C2, C1] D3, D2, D1	DF6, DF5, DF4 [CF6, CF5, CF4, CF3, CF2, CF1] DF3, DF2, DF1 Scales divided at ⁶√10.	Duplex 400 mm x 1¾ x ¼ in	"Precision Duplex." (Originally known as "Ultra Accuracy.") Four digit precision. Scales are divided into six segments, each 400 mm long. Early production has scale labels in green on cursor. U S Patent 2235106A, March 18, 1941.
201	1967-69	Pic	L2.4, L1.3, A2.4, A1.3 [C4, C3, C2, C1] D1, D2, D3, D4	K4, K3, K2, K1 [CF4, CF3, CF2, CF1] DF1, DF2, DF3, DF4 Scales divided at ⁴√10.	Duplex 500 mm x 1¾ x ¼ in	"Sold in Japan." Scales are divided into four segments each 500 mm long. Early production has scale labels in green on cursor.
250	1950-EOB	Pic	DF [CF, CIF, CI, C] D, L Folded at √10.	K, A [B, TI₂, TI₁, SI] D, DI	Duplex 250 mm x 1 5/8 x ¼ in	"General Engineering and Business." Replaced models 150 and 2600. About a third have anodized black end brackets.
251	1951-58	Pic	L, DF [CF, CIF, CI, C] D, DI Folded at π.	K, A [B, T, S, ST, C] D, LL3, LL2, LL1	Duplex 250 mm x 1 5/8 x ¼ in	"Mechanical Engineer."
1958-EOB	Pic	L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	K, A [B, T, S, ST, C] D, DI	H-O 1773
P253	1961-EOB	Pic	LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.	K, A [B, TI₂, TI₁, SI] D, DI. TI divisions= 1/12 degree	Duplex 250 x 41 x 5 mm	Vectolog." Elaborate clamshell case. All-plastic version of model 264. ¥2.400 in catalog 6911.	H-O 1774-00 (-1964); Geotec 341-3130 (1964+)
P253 Special	1967	Pic	LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.	K, A [B, TI₂, TI₁, SI] D, DI	Marked "P253 Special" and "Vectolog." Only difference from P253 is green CIF scale.
1965	Pic	LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.	K, A [B, TI₂, TI₁, SI] D, DI,√3V.	Marked "P253 Special" and "Vectolog." Short additional scale on back marked "√3V" at left and and "volt" at right end.
254W	1963-68	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10.	K, A [B, TI, SI, C] D, DI, L	Duplex 250 mm x 1¾ x ¼ in.	"High School Students". Basis for model 108 demo rule. Equal length stators.
1963-72	Pic	Traditional stators.
254 W-S	1970s	Pic	Same as 254W but folded at π.	Same as 254W.	Only difference from 254W is where front scales are folded.	Only two specimens known. Date codes "RC" (March 1967) and "UB" (Feb 1970)
1969	Pic	Same as 254W. Folded at √10.	L, K, A [B, TI, SI, P] Q, Q', D, DI	With P, Q, and Q' scales	Date code "TC" = March 1969.
1970s	Pic	K, A, [SIN COS, COS², TI, SI, C] D, DI, L	With stadia scales.	Equal stators date = "OC" (Mar 1964); others = "UB" (Feb 1970) or no code.
1971	Pic	K, A [B, TI₂, TI₁, SI, C] D, DI, L	"High School Students." Traditional stators. Hemmi name on back of rule.
1971	Pic	Same as 254W but folded at π.	K, A [B, TI₂, TI₁, SI, C] D, DI, L	Date code "VC" = March 1971
1970s	Pic	KI, K, AI, A [B, S, T, CI, C] D, LdB, P, DI	May set record for number of different inverse scales on one side of a rule.
1965	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, ST, CI, C] D, LL3, LL2, LL1 Folded at π.	KI, K, AI, A [B, S, T, CI, C] D, LdB, P, DI	Equal length stators.
254WN	1972-EOB	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10.	LL/0, K, A [B, TI₂, TI₁, SI, C] D, DI, L, LL0	"High School Students." Traditional stators. Hemmi name and model number on back of rule.
254 WN-S	1972	Pic	Same as 254WN except folded at π.
1973	Pic	Same as 254WN. Folded at √10.	L, K, A, [B, TI₂, TI₁, SI, P] Q, Q', D, DI
255	1950-57	Pic	L, K, DF [CF, CIF, CI, C] D, χ, θ Folded at π.	Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D,LL3,LL2,LL1	Duplex 250 mm x 1¾ x ¼ in	"Expert Electrical Engineer." Replaced model 155.
1958-61	Pic	L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, χ, θ
255D	1961-EOB	Pic	L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, DI, χ, θ
256	1950-68	Pic	L/dB, Neper, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	A, Ĺ [Ċ, SI, TI] D, l, F	Duplex 250 mm x 1¾ x ¼ in	Electrical Communications. Ĺ and Ċ scales are about half length.
257	1952-68	Pic	L, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	Ch A-M, Ch N-Z, M₁ [M₂, ^oF, ^oC, ^oK, F(t)] Kg/cm², mm Hg, in. Hg Vac., t_ω	Duplex 250 mm x 1¾ x ¼ in	"Chemical Engineer."	Post 1491 (c1957-67); H-O 1770 (-1958-)
257L	1971-EOB	Pic	L, K, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	Ch A-M, Ch N-Z, M₁ [M₂, ^oF, ^oC, ^oK, LM] mm Hg, Kg/cm², in. Hg Vac., t_ω	"Chemical Engineer." Hemmi name on back of rule.
258	1951	Pic	LL0, LL/0, K, DF [CF, CIF, CI, C] D, R₁, R₂, L Folded at π.	LL/1, LL/2, LL/3 [T T, SecT ST, Cos S, C] D, LL3, LL2, LL1	Duplex 250 mm x 1¾ x ¼ in	VERSALOG Ia. About 30 specimens marked "Hemmi 258" are known. All are also marked "THE FREDERICK POST CO. NO 1460" or "THE HUGHES OWENS CO. LIMITED NO. 1777." Click here for a short history of model 258.	Post 1460 Versalog (1951+); H-O 1777 Versalog (1951+). For information about Versalog models Ib and II see the second page of this Catalogue Raisonne.
259	1950-58	Pic	L, K, DF [CF, CIF, CI, C] D, LL0, LL/0 Folded at π.	LL/1, LL/2, LL/3, A [B, T, S, ST, C] D, LL3, LL2, LL1	Duplex 250 mm x 1¾ x ¼ in	"Expert Mechanical Engineer." Replaces model 159.
1958-63	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π	L, K, A [B, T, S, ST, C] D, LL0, LL/0	"Expert Mechanical Engineer." Hemmi name moved to back of rule.
259D	1953-EOB	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π	L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0
259D-S	1970s	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	LL0, LL/0, K, A [B, T, S, ST, C] D, √1, √2, L
260	1964-EOB	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	LL/0, LL0, K, A [B, T, S, ST, C] D, DI, P, L	Duplex 250 mm x 1¾ x ¼ in	"Advanced Engineer." {3 hairlines: A: C², hp-C²} Some rules c1970 have brand and model on bottom edge. Some marked UNIVERSITY on bottom edge. ¥4,800 in catalog 6911.
260 Demo	1964	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	LL/0, LL0, K, A [B, T, S, ST, C] D, DI, P, L	Duplex 1500 mm x _	Painted wood classroom demonstration rule. Cursor is single wire.
P261	1965-EOB	Pic	LL01, LL02, LL03, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	T, ST, K, A [B, BI, CI, C] D, L, P, S	Duplex 250 x 46 x 5 mm	"Advanced Engineer" (Darmstadt). Stators white or pale blue. {4 hairlines on back of cursor. A: C2, hp-C2, D: C}	T-P 1420 (c1971 only) T-P 44CB-200 (1972+) Geotec 341-3660
P262	1965-EOB	Pic	LL01, LL02, LL03, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	K, A, R1, R2 [T2, T1, ST, S, C] D, L, LL00, LL0	Duplex 250 x 46 x 5 mm	"Advanced Engineer" (Rietz).	T-P 1422 (c1971 only), T-P 44CB-220 (1972+)
P263	1964-69	Pic	P₁, P₂, DF [CF, CIF, CI, C] D, LL, LL Folded at 360.	A, N [M, £, S/d, C] D, G	Duplex 250 x 41 x 5 mm	"Commerce." N, M have 365 divisions for dates. £,S/d = pound, shilling/pence. G is a set of conversion gauge marks	Geotec 341-3155 (1967+) Hemmi 143 is pocket version.
264	1968-EOB	Pic	LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10	K, A [B, TI₂, TI₁, SI] D, DI.	Duplex 250 mm x 15/8 x ¼ in	Bamboo version of model P253, Vectolog.
264-S	1969	Pic	K, A [B, TI, SI, P] Q, D, DI.	P & Q scales, Single TI scale.
264-M		Pic	K, A [B, TI₂, TI₁, SI] D, DI.	A mis-marked model 264? Only known specimen was sold on Yahoo Japan, June 2018. Photo shows factory marking "264-M."
264-S	1970s	Pic	LL3, LL2, DF [CF, CIF, CI, C] D, LdB, LL1 Folded at √10.	K, A [B, TI₂, TI₁, SI] D, DI, χ, θ
P265	1968-72	Pic	P₁, P₂, DF [CF, CIF, CI, C] D, LL2, LL1 Folded at 360	A, D [G, 0-24, N] M, 0-24	Duplex 250 x 46 x 4 mm	"Business." N, M have 365 divisions for dates. G is a set of conversion gauge marks. Instructions & scale labels in Japanese.
266	1961-EOB	Pic	(LL/3 and LL/1), LL/2, LL2, A [B, BI, CI, C] D, dBL, S, T	X_L, X_C, F, (τ₁ and P), [(τ₂ and Q), L, C, C_z] L, Z, f_o	Duplex 250 mm x 1¾ x ¼ in	"Electronics." Announced in 1961 but not in Hemmi catalogs until 1966. Early specimens (1962) marked "Developed by SONY." LL/3, LL/1, τ₁, τ₂, P, Q are partial length scales. Also sold as Geotec 341-3550 (1966+)
P267	1971-EOB	Pic	³√-3, ³√-2, ³√-1, DF [CF, CIF, CI, C] D, √-1, √-2, δ(unif.) Folded at √10	4√-4, 4√-3, 4√-2, 4√-1 [λ_δ(conc), λ_δ(Trape), λ_M, P] Q, L, T, S	Duplex 250 x 46 x 5 mm	"Structural Design."
269	1965-EOB	Pic	L, F, K, A [B, K', CI, C] D, LL3, LL2, LL1	CL, SL, M, TL [R, ST, T, S, C] D, DI, SinCos1, SinCos2	Duplex 250 mm x 1¾ x ¼ in	"Civil Engineer."
P270	1971-EOB	Pic	J, J [T(ºK), Q(m³/s), Q(m³/s)] Hm(m), Q(m³/s), Ht(m)	X, X, Cz, Cmax(PPM) [He(m), Cy, CI, C] D, A, L	Duplex 250 x 46 x 5 mm	"Pollution A." (air quality analysis) 19 scales in black, red and blue.
P271	1974	Pic	x,x_s(g/kgDA), (ice), T_φ,t_φ(ºC) [h_w,h_s(mmhg), CI, C] D, v, v_a(m³/kgDA), t(ºC), t(ºF)	[t(ºC)(ice), t'_2.5, t(ºC)]	Open 250 x 46 x 5 mm	Moist air. There are 13 scales--most with complicated labels.
274	1973-EOB	Pic	L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10	K, A [B, TI₂, TI₁, SI, C] D, DI	Duplex 250 mm x 1¾ x ¼ in	Late model general engineering rule with scales folded at √10 and trig scales inverted. Likely sold only in Japan.
274-S	Pic	K, A [B, TI₂, TI₁, SI, C] D, DI, dB
NA	dB, K, A [B, TI₂, TI₁, SI, C] D, DI, χ, ϴ
275	1950-58	Pic	L, K, DF [CF, CIF, CI, C] D, χ, θ Folded at π.	Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, LL3, LL2, LL1	Duplex 500 mm x 1¾ x ¼ in	20-inch Version of Model 255.
1958-63	Pic	L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, χ, θ	20-inch Version of Model 255. Some with green scale labels on cursor.
275D	1963-69	Pic	L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, DI, χ, θ	20-inch Version of Model 255D. Some with green scale labels on cursor.
279	1950-58	Pic	L, K, DF [CF, CIF, CI, C] D, LL0, LL/0 Folded at π.	LL/1, LL/2, LL/3, A [B, T, S, ST, C] D, LL3, LL2, LL1	Duplex 500 mm x 1¾ x ¼ in	20-inch Version of Model 259. Some with green scale labels on cursor.
1958-63	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.	L, K, A [B, T, S, ST, C] D, LL0, LL/0
279D	1963-69	Pic	LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL Folded at π.	L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0	20-inch Version of Model 259D. Some with green scale labels on cursor.
P280	1959-72	Pic	T, K, A [B, CI, C] D, L, S, ST	[LL1, LL2, LL3]	Open 250 x 46 x 4 mm	"Beginners."	T-P 1414 (c1971 only), 44BB-140 (1972+); Geo 341-3645; Ahrend P280.
280S	1976?	Pic	L, K, A [B, CI, C] D, S, ST, T	cm [LL1, LL2, LL3] inches	Open 250 mm	All plastic. Marked "HEMMI, JAPAN, 280S" but probably made by D&P. Only known specimen found in Thailand	Ahrend P281; Same as Aristo 0903 except back of Aristo slide is blank.
P281	1970-72	Pic	T, K, A [B, CI, C] D, L, S, ST	Blank	Open 250 x 46 x 4 mm	Rietz.	T-P 1410 (c1971 only), 44BB-100 (1972+); Geo 341-3640
P283	1970-71	Pic	K, A, DF [CF CI, C] D, L, T, S Folded at π.	[LL1, LL2, LL3]	Open 250 x 46 x 4 mm	Beginners.	Ahrend P283.
Models 300-999: Specialty Slide Rules
300	WWII	Pic	G, E [F, CI, C] D, M	[Blank]	//Closed\|\| 250 x 34 x 8.5 mm	Decimal Calendar Rule. G scale is folded at 365; E & F folded at 3.042 = 365/12. M scale is set of gauge marks for Japanese weights & measures. Japanese language.
301 301A	1954-69	Pic	τ, ω [CI, f, P, C] D, A, db	[θ, θd, g', g]	//Closed\|\| 250 x 34 x 11 mm	Control Engineering. Four cursors! 301A is 301 plus a transparent overlay.	Post 1490 (1957-ca67)
305	1959-70	Pic	TmV/S, ℓ₁ [ℓ₂, m, a] T, v	[N, F, u]	//Closed\|\| 125x26 x _ mm	Acoustic Design. Patents 225936, 225937.
400	1959-68	Pic	Y, A [B, CI, C] D, LL3, LL2, LL1	E_ß, R(AI), Dist, Dose Rate [S, Isotopes (4 scales)] E_v, Pb, Fe, Al	Duplex 250 mm x 1¾ x ¼ in	Radioisotope Engineering.
401	1966-69	Pic	d, W [Nt, D, MI, M] L	τo, P [d, D, D, Na(δ)] k(P), d	Duplex 250 mm x 15/8 x ¼ in	"Coiled Spring Rule."
P402	1966-69	Pic	15 scales in black, red, blue and green -- all labeled in Japanese. Only three scales are full length. Scale arrangement and range of variables differs slightly between the two models.	A, DF [CF, CIF, CI, C] LL (2 scales) Folded at √10.	Duplex 250 x 41 x 5 mm	"Tanabe Corporate Performance Analysis." P402 for manufacturing businesses; P403 for wholesale and retail distributors. Rule and instructions in Japanese.	Click here for an illustrated explanation of models P402 and P403 by Atsushi Tomozawa.
P403	1966-69	Pic
405	1950-68	Pic	C₂F, Al₂O₃ [Fe₂O₃, C₂AF] C₂A, SO₃, CaSO₄	C₂S (A Scale), CaO [SiO₂(for C₃S), Fe₂O₃, SiO₂(for C₂S), SO₃/Al₂O₃] C₃S, C₂S (B Scale)	Duplex 250 mm x 1¾ x ¼ in	"Cement Composition." Scale labels are chemical symbols, numbers subscripted. No scales are logarithmic. Fe2O3 and SiO2(for C2S) are separate short scales on same line. Accompanying Instruction Manual published by Portland Cement Assoc. Skokie, Ill, May 1959.
410	1959-69	Pic	G₂, G₁, F₂, F₁ [x, F₁G₁] Z₁+Z₂, G', F'	G₂, G₁, F₂, F₁ [x, CI, C] D, A	Duplex 250 mm x 1¾ x ¼ in	"Involute of Gear Wheel."
451	1969	Pic	Eight specialized scales. Center scales are not full length.	LL/3, LL/2, LL2, A [B, BI, CI, C] D, dBL, S, T	Duplex 250 mm	"Field Intensity." There are bamboo and all-plastic versions of this rule; both are marked "451." (Not "P451")
P452	1968-72 (For Post)	Pic	LL1, LL2, LL3, CR_DF [T_CF, CIF, %_CI, T_C] R_D, L, in, cm Folded at π	ST, 3n-2_K, 2n-1_A [B, BI, CI, C] D, P, S, T	Duplex 250 x 46 x 4 mm	"Business." Some marked "System H. Kroon." Yellow slide, green brackets. (Post & T-P have blue slide & brackets)	T-P 1426 (c1971 only), 44CB-260 (1972+)
500	1943	NA			125 mm x _	"For Airplane." ¥8.50 in 1943 price list. No other mention.
640S	1972	Pic	K, DF [CF, CIF, CI, C] D, A, L Folded at √10.	[STI, TI₂, TI₁, SI, CI]	//Closed\|\| 250 x 45 x 9 mm	Desk Rule. Bamboo between thick plastic
641	1975	Pic	K, A, DF [CF, CIF, B, CI, C] D, DI, L Folded at √10	[STI, TI₂, TI₁, SI, CI]	//Closed\|\| 250 x 45 x 9 mm	Desk Rule. Bamboo between thick plastic.
642T	1973	Pic	K, A [B, BI, CI, C] D, DI, L with over-range	[T₂, T₁, ST, S]	//Closed\|\| 250 x 45 x 9 mm	Desk version of 64T. Bamboo between thick plastic. {3 hairlines: D: C, C}.	Ahrend 643T
651	1969	Pic	K, A, DF [CF, CIF, B, CI, C] D, DI, L Folded at √10.	[TI₂, TI₁, STI, SI, C]	//Closed\|\| 250 mm x 1½ x 7/16 in
Models 1xxx: Circular Slide Rules
1001	1971	Pic	A, D, C, CI, L	Blank	Circular 80 mm	Circular.	Geotec 341-3910
1002	1971	Pic	A, D [C, CI]	Blank	Circular 80 mm	Circular. Less elaborate than 1001.
2600 Series Rules Introduced in 1940 (February 11, 1940 was the 2600th Aniversary of the Founding of Japan)
2600	1940-51	Pic	DF [CF, CI, C] D, L Folded at √10.	K, A [B, TI₂, TI₁, SI₁] D, DI	Duplex 250 mm x 15/8 x ¼ in	General Engineering and Business.
2634	1949-EOB	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[TI₂, TI₁, L, SI]	//Closed\|\| 125 x 26 x 5 mm	Pocket 2664.
P2634		Pic	K, DF [CF, CI, C] D, A Folded at √10.	[TI₂, TI₁, L, SI]	\|\|Closed\|\| 125 mm x _
2640	1949-68	Pic	ℓ, A [B, CI, C] D	[S, K, T] (S keyed to C/D)	\|\|Closed\|\| 200 x 28 x 8 mm	Beginners Slide Rule for 50W. Plastic cursor.
2641		Pic	DF [CF, CI, C] D, A Folded at √10.	Blank	\|\|Closed\|\| 200 x 28 x 8 mm	Beginners Slide Rule for 45 (which, itself, was a beginner's rule). Plastic cursor.
2645	WWII	Pic	DF [CF, CI, C] D, A Folded at √10.	[TI, L, SI]	Closed 200 x 28 x 8 mm	Essentially identical to model 45 except CI scale is black.	Only one specimen known.
2662	1966-69?	Pic	K, A, DF [CF, CIF, CI, C] D, DI, L Folded at √10.	[B, TI, SI, C]	//Closed\|\| 250 x 34 x 11 mm	Some with 13-0-13 cm scale on bottom edge.	See Hemmi Catalogue Raisonne 2 for a slide projector version of this rule.
2664	WWII	Pic	K, DF [CF, CI, C] D, A+L Folded at √10.	[TI₁, TI₂, SI₂, SI₁]	\|\|Closed\|\| 250 x 34 x 9 mm	Wartime construction (bare vertical edges and back) No model number on rule. A+L scale is left half of A scale joined to right half of L scale.
MIOJ	Pic	K, DF [CF, CI, C] D, A Folded at √10.	[TI₂, TI₁, L, SI₁]	//Closed\|\| 250 x 34 x 11 mm	Better quality construction. Full length A scale; L scale replaces SI_2.
1949-58	Pic	K, DF [CF, CI, C] D, A+L Folded at √10.	[TI₁, TI₂, SI₂, SI₁]	A+L scale is left half of A scale joined to right half of L scale.
2664S	1958-69	Pic	K, DF [CF, CIF, CI, C] D, A Folded at √10.	[TI₂, TI₁, L, SI]	//Closed\|\| 250 x 34 x 11 mm	Same as 2664 except 10 mm longer overall and green CIF scale added.	¥2,200 in catalog dated 6911
2664S-S	1967	Pic	K, A, DF [CF, CIF, CI, C] D, DI Folded at √10	[TI₂, TI₁, L, SI]	//Closed\|\| 250 x 34 x 11 mm	Same as 2664S except DI scale added.
2670	MIOJ	Pic	K, A [B, CI, C] D, L	[S, S&T, T]	//Closed\|\| 500 x 40 x 12 mm	Long Rietz. Short-lived replacement for model 70. {3 hairlines: D: C, C}.
2690	1951-68	Pic	L, D [M1, M2, C] D, A	[S, S&T, T]	//Closed\|\| 250 x 34 x 11 mm	Stadia. {3 hairlines: D: C, C}.
2690A	1954-55	NA	Same as 2690	"2690A" marked on case to distinguish model 2690 from proposed centesimal degree model 2690B. Rules are marked just "2690."
Odds and Ends
P3526	1970s?	Pic	S, K, A [B, CI, C] D, L, T	None	\|\|Closed\|\| 250 x 40 x 3 mm	Beginner's all-plastic slide rule marked "HEMMI, Japan, NO P3526" but manufactured by Hope Slide Rule Mfg Co, Tokyo. Same as Hope model 51. (The only known 'Hemmi' example was found in New Zealand.)

Model

Dates

Front Scales

Rear and Other Calculating Scales

Body

Comment

Also Sold As

Models1-18: Obsolete Model Numbers Abandoned About 1930.

1
1/1

1913-29

Pic

A [B, C] D

[S, L, T]

//Closed||
250 x 28 x 9.5 mm

Mannheim. ("Normal") Listed as obsolete starting in 1936 but price listed in Hemmi catalogs through 1937 and available from Frederick Post (as model 1449) through 1940.

Tamaya 1941 (1916-27);
H-O 1768 (-1914-);
Post 1449 (1930-WWII)

Pic

Artillery variant with minutes and mils conversion scales on bottom edge and trigonometric formulas for gunnery on back of rule. Dates probably later than model 1.

Pic

A [B, Stadia, C] D

Stadia variant. Stadia scale (SinCos and Cos²) added to front of slide. Dates probably later than model 1.

1913-29

Pic

Same as model 1 but with decimal-indicating cursor.

//Closed||
250 x 28 x 9.5 mm

Discontinued ca1929.

Tamaya 1937 (1913-27);
H-O 1767 (-1914-28-)

1919-29

Pic

LL2, A [B, C] D, LL3

[S, L, T]
Gutter: E, F

//Closed||
250 mm
x 1½ in x 10 mm

Electro. (Copy of Faber 378) LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No over-range. HP gauge mark (probably only 746). Single hairline. At least three different cursors. Tamaya 1905 (1919-27); H-O 1770 (1928), Hemmi 80 (1930+).

1919-29

Pic

Same as 3 but with decimal-indicating cursor.

Tamaya 1904 (1916-27), Hemmi 81 (1930+

1919-29

Pic

A [B, C] D

[S, L, T]

//Closed||
500 mm x 1¼ x 13/32 in

Listed as obsolete by Hemmi in 1936 but price listed through 1937. In Post catalog (model 1450) until WWII and in H-O catalog (model 1772) though1948.

Tamaya 1899 (1916-27);
H-O 1772 (1928);
Post 1450 (1936-WWII).

1919-29

Pic

A [B, C] D

[S, L, T]

//Closed||
125 x 24 x 9 mm

Pocket Mannheim. Replaced by model 48 ca1930.

H-O 1763 (-1914-35);
Tamaya 1942 (1916-27).

1926-29

Pic

Same as 6 but with decimal-indicating cursor

Tamaya 1949 (1927)

1913-29

Pic

A [B, C] D

[S, L, T]

/Closed||
125 x 24 x 9 mm

Extra Fine Mannheim w Magnifier.

Tamaya 1943 (1916-27);
H-O 1764 (-1914-48-)

1919-29

Pic

Same as 8 but with magnifiying decimal-indicating cursor

Discontinued ca1929.

Tamaya 1900 (1916-27)

1926-29

Pic

A [B, C] D

[S, L, T]

//Closed||
250 mm

Ten-inch extra fine with "extended lens" magnifier. Discontinued ca1929.

Tamaya 2148 (1927)

1926-29

Pic

Same as10 but with decimal-indicating "extended-lens" cursor.

Discontinued ca1930.

Tamaya 2180 (1927)

DF [CF, CI, C] D
(Folded at ?)

Blank

?
150 mm

Simplified Slide Rule. Plastic.
Single uncorroborated reference.

1926-29

Pic

Same as model 3 but with "extended-lens" magnifying cursor.

Discontinued ca1929.

Tamaya 2782 (1927)

1926-29

Pic

Same as 4 but with decimal-indicating "extended-lens" cursor.

Discontinued ca1929.

Tamaya 2783 (1927)

1926-29

Pic

A [B, C] D

[S, L, T]

||Closed||
100 mm
x 11/16 x 7/32 in

Vest Pocket Mannheim with square edges.

Tamaya 2784 (1927);
Hemmi 35 (1930+)

1926-29

Pic

Same as 14 but with decimal-indicating cursor.

Discontinued ca1929.

Tamaya 2785 (1927)

1926-29

Pic

Same as 14 but with magnifying cursor.

Discontinued ca1929.

Tamaya 2786.
Hemmi 35ML (1930+)

1926-29

Pic

Same as 14 but with magnifying decimal-indicating cursor.

Discontinued ca1929.

Tamaya 2787

1826-29

Pocket kit including pen, pad and model 15 slide rule.

Discontinued ca1929.

Tamaya 2788

1927

Pic

A [B, C] D

[S, L, T] ?

250 mm

Student version of model 1. Model number may have been changed to 40 before any were actually sold.

Model Numbers 20-24 were assigned to Classroom Demo Slide Rules before WWII; Student Rules after WWII.

1932-42

A [B, CI, C] D, K

[S, L, T]

Demo
2000 mm

Demonstration Mannheim (Model 50)

Tamaya 4451 (1932)

1932-42

K, A [B, CI, C] D, L with over-range

[S, S&T, T]

Demo
2000 mm

Demonstration Rietz (Model 64).

Tamaya 4452 (1932)

1951-59

Pic

[CI, C] D, A

No back

Special
200 x 23
x 9 mm

Cheap student rule distributed in Asia only. Slide held to single stator. Some (1955 only?) sandalwood, not bamboo. Celluloid cursor.

P23

1957-69

Pic

A [B, CI, C] D

Open
180 mm
x 1 x 1/8 in

Student Mannheim w CI scale.
Hemmi's first plastic-based rule.

1927

Pic

A [B, C] D

Blank

//Closed||
125 x 26 x 3 mm

Ultra-thin all plastic with celluloid cursor. 13 cm scale on top edge; bottom blank. Identical to model 34 except imprinted with advertising. Rare. Appears in no known catalog.

P24

1963-69

Pic

DF [CF, CI, C] D, A
Folded at √10.

Blank

Open
180 mm x 1 x 1/8 in

Student.

Models 30-39: Miscellaneous Four- and Five-inch Closed Body Slide Rules

1930-43

Pic

A [B, C] D

[S, L, T]

//Closed||
100 mm x 11/16 x 7/32 in

Vest Pocket Mannheim. Model number never appears on rule. Some w "SUN" cut through or "SKF" embossed into backing plate. 1000¥ ($2.78) in 1969.

Tamaya 4453 (1927);
Post 1447 (1931-33);
Post 1440 (1934-WWII)

1930-42

Pic

Same as 30 but with decimal-indicating cursor.

No CI scale

Tamaya 4454

1930-42

Pic

Same as 30 but with magnifying cursor.

Tamaya 4455; Post 1447M (1931-33); 1441 (1934-WWII);
Boston Blue Print 1441; US Blue 1888.

1930-42

Pic

Same as 30 but with decimal-indicating magnifying cursor

No CI scale

Tamaya 4456

30R

MIOJ-1950

Pic

A [B, CI, C] D

[S, L, T]
(S keyed to A/B except WWII-1955 keyed to C/D)

//Closed||
100 mm x 11/16 x 7/32 in

Vest Pocket Mannheim w CI scale. No model number on rule but case and box marked "30R."

Fuji 41.
Post 1440.

1951-EOB

Pic

Same rule with "R" dropped from model number on case and box. All-plastic cursor after ca 1970.

32R

MIOJ-1950

Pic

Same as 30R but with magnifying cursor

Post 1441(WWII-1971); T-P 44DA-410 (1972+);
H-O 1760 (-1952-64); Geo 341-3405 (1964+)
US Blue 1888 (MIOJ)

1951-EOB

Pic

Same as 30 but with magnifying cursor.

P33S

1971

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to C/D)

Closed
125 x 28 x 5 mm

Pocket Improved Mannheim. All-plastic version of model 34RK.

P33/SS

1970

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to C/D)

Closed
125 x 27 x 4.5 mm

Pocket Improved Mannheim. Unique size.

Geotec 341-3610

1932

Pic

A [B, C] D

Blank

//Closed||
125 x 26
x 3 mm

Ultra-thin all plastic with celluloid cursor. 13 cm scale on top edge; bottom blank

Hemmi 24;
Tamaya 4457

34P

1932-42

A [B, C] D

Blank

//Closed||
125 mm x 15/16 x 5/32 in

Thin Pocket Mannheim with blank back.

Post 1443 (1931-WWII)

MIOJ

Pic

//Closed||
125 x 26 x 5 mm

34π

1932-42

Pic

CF [DF, CI, C] D
Folded at π

[S, L, T]
(S keyed to C/D)

//Closed||
125 mm x 15/16 x 5/32 in

Thin Pocket Mannheim with folded scale.

Post 1444 (c1935-WWII);
H-O 1762 (-1935-WWII)

MIOJ

//Closed||
125 x 26
x 5 mm

34R

1935-40

Pic

A [B, CI, C] D

[S, L, T]
(S keyed to A/B except WWII-1955 keyed to C/D)

//Closed||
125 mm x 15/16 x 1/8 in

Thin Pocket Mannheim w CI Scale.

Post 1444 (c1935-WWII);
H-O 1762 (-1935-WWII)

1955-68

//Closed||
125 x 26
x 5 mm

34RK

1936-EOB

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to A/B except WWII-1955 keyed to C/D)

//Closed||
125 x 26
x 5 mm

Post 1444K (1937-70),1444(1971); T-P 44DA-440 (1972+);
US Blue 1887 (1930s); H-O 1762 (WWII-64); Geo 341-3425 (1964+).

34T

1936-42

Pic

A [B, C] D

[S, L, T]

//Closed||
125 mm x 15/16 x 1/8 in

Thin Pocket Mannheim. "SUN" or ASEA embossed into backing plate.

1935-48

Pic

A [B, C] D

[S, L, T]

||Closed|| 100 mm x 11/16 x 3/16 in

Vest Pocket Mannheim with 4-inch and 10-cm measuring scales on square edges

Hemmi 14;
Post 1437 (c1935-WWII);
H-O 1761 (-1935-48-)

35ML

1930s

Pic

Same as 35 but with magnifying cursor

Hemmi 16

P35
B35

1959-61

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

Blank

Open
115 mm x 1 x 1/8 in

Marked "B35" (factory error for "P35"?); thin bamboo core covered with PVC (not celluloid); scales printed (not engraved). All known specimens also marked H-O 1759.

P35S

1971

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[LL1, LL2, LL3]

Closed
125 x 28 x 4.6 mm

1936-WWII

Pic

A [B, CI, C] D

[S, L, T]

Closed
125 mm x ¾ x 7/32 in

Narrow Pocket Mannheim w CI scale. Measuring scales on BACK of rule.

Post 1438 (c1935-WWII)

P36
P36S

1966-70

Pic

D [Conversion gauge marks, A] D

Instructions [Conversion gauge marks, B] Instructions

Open
115 mm x 1 x 1/8 in

Rule is labeled "P36;" box and instructions "P36S." Set arrow on slide opposite value on top D scale; converted value appears on bottom D scale opposite corresponding arrow. Reverse slide for more conversions. Markings and instructions in Japanese. 450¥ ($1.25) in 1969.

P37

1966-70

Pic

(1), (2), D [C, CI, B] MD1, MD2

[B, PR1, PR2, PR3]

Closed
125 x 28 x 4.6 mm

SALES. Labeled in Japanese. MD1 is months and days from 1/1 to 6/30, MD2 from 7/1 to 12/31. PR1-2-3 = three short profit ratio scales. Reverse slide to read B, PR scales.. {Two hairlines: D: 1.2}. 700¥ ($1.94) 1969.

P39

K, A, DF [CF, CIF, CI, C] D, DI, L
Folded at ?

[B, TI, SI, C]

Closed
125 mm

Single uncorroborated reference.

Models 40-49: Basic Mannheim Rules (A [B, C] D) before WWI and "Improved" Mannheim (A [B, CI, C] D, K) after WWII.

1932-49

Pic

A [B, C] D

[S, L, T]

Closed
250 x 28 x 8 mm

Tamaya 4458 (1927), Post 1446 (1931-49); H-O 1768 (-1935-48-); Boston Blue Print 1446; US Blue 1876 (1930s); Lietz 2974N (1930s).

1932-42

Pic

A [B, C] D

[S, L, T]

Closed
125 mm

Pocket Mannheim. No measuring scales

Tamaya 4459 (1932)

1932

Pic

A [B, C] D

[S, L, T]

Closed
250 x 28 x 8 mm

Model 40 w measuring scales on BACK.

Tamaya 4460 (1932)

1932

Same as 42 but with decimal-indicating cursor.

Tamaya 4461 (1932)

1932

Pic

A [B, C] D

[S, L, T]

Closed
125 mm x 15/16 x ¼ in

No slant; cm & inch scales on back of rule.

Tamaya 4462 (1932)

1932

Same as 44 but with decimal-indicating cursor.

Tamaya 4463 (1932)

1949-68

Pic

DF [CF, CI, C] D, A
Folded at √10.

[TI, L, SI]

Closed
200 x 28 x 8 mm

Student. Quite different from 1932 model 45.

1936-42

Pic

A [B, C] D

Blank

Special. 125 mm x 1 in

"Cardboard covered in transparent celluloid with leather sheath."

1936-42

Pic

A [B, C] D

[S, L, T]

//Closed||
250 x 28 x 8 mm

Thin successor to model 1/1.

Post 1449T (1937-WWII)

1932-42

Pic

A [B, C] D

[S, L, T]

//Closed||
125 mm x 15/16 x ¼ in

Pocket Mannheim. Thin successor to model 6.

40F

1968-69

Pic

K, DF [CF, CI, C] D, A
Folded at √10

[TI, L, SI]

Closed
250 x 28 x 8 mm

Fuji 85.

40RK

1949-69

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to A/B except Staedtler 944-55 keyed to C/D)

Closed
250 x 28 x 8 mm

Improved Mannheim. ("Slide Rule with CI and K Scale" in early literature)

Post 1447 (c1949-1971);
H-O 1768C (-1952-64);
Geo 341-3526 (1964-71);
US Blue 1877 (1940s?).

1973

Pic

Same as preceding but wider with thick plastic back.

Closed
250 mm x 1¼ x 9/32 in

T-P 44BA-470 (1972+);
H-O 341-3526 (1972+)

40-50

Pic

Overhead projection rule for Hemmi model 40RK.

Projection 305 x 182 x 12 mm

P
40RK

1967-69

Pic

A [B, CI, C] D, K

[S, L, T]

Open
250 x 28 x 8 mm

All-Plastic Improved Mannheim. Hard plastic case.

Post 1447P (c1967);
Geo 341-3530 (c1967)

43A

1961-71

Pic

A [B, CI, C] D, K

[T, L, S]
(S keyed to C/D)

Closed
200 x 28 x 8 mm

Student Improved Mannheim.

P43D

1973-EOB

Pic

A [B, CI, C] D, K

[T, L, S]
(S keyed to C/D)

Closed
200 x 28 x 6.4 mm

Like 43S except no indices on back of rule; slide must be reversed.

P43S

1969

Pic

A [B, CI, C] D, K

[T, L, S]
(S keyed to C/D)

Closed
200 x 28 x 6.4 mm

Plastic version of 43A. Indices for reading trig scales on back of rule.

45K

1962-EOB

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[TI, L, SI]

Closed
200 x 28 x 8 mm

Post 1445 (c1966-71); T-P 44BA-450 (1972+);
Geo 341-3500 (1967+).
All have scales folded at π.

P45K

1965-69

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[TI, L, SI]

Open
200 x 28
x 5 mm

Open body all-plastic version of 45K

Post 1445P (-1965-)
Scales folded at π.

P45D

1973-EOB

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[T, L, S]

Closed
200 x 28 x 6.4 mm

"Junior High School Students." Like P45S except trig scales not inverted and no indices on back of rule; slide must be reversed.

P45S

1969-73

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[TI, L, SI]

Closed
200 x 28 x 6.4 mm

Closed body all-plastic version of 45K. Simpler construction than P45K.

Models 50-59: "Improved" Mannheim Slide Rules (A [B, CI, C] D, K and [S, L, T]) and Variants.

50, 50/1,
50/3

1932-51

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to A/B except WWII-1955 keyed to C/D)

//Closed||
250 x 28 x 10.5 mm

Improved Mannheim. Formerly model 102.

Hemmi 102; Tamaya 4464 (1932); Post 1452 (c1935-51); H-O 1771 (-1928-48-);
US Blue 1880 (1930s).

50F, 50/1F

1936-MIOJ

Pic

A [B, CI, C] D, K

[S, L, T]

//Closed||
250 x 28 x 8 mm

Thin version of 50, 50/1 but accepts standard cursor.

Post 1452T (1936-WWII).

50π/1

1936-42

Pic

A, DF [CF, CI, C] D, L
Folded at π.

[S, S&T, T]

//Closed||
250 x 28 x 10.5 mm

Post 1455 (c1935-WWII).

50W

1951-EOB
(For Post)

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to A/B except WWII-1955 keyed to C/D)

//Closed||
250 x 34 x 11 mm

Wide Improved Mannheim.

Post 1452W ('51-70), 1452 ('71); T-P 44BA-520 ('72+);
H-O 1771 ('51-64);
Geo 341-3215 ('64+).

P50

1965?-68?

A [B, CI, C] D, K

Blank

Open?
250 mm x 1½ in

Improved Mannheim.

50-20

1935-48

Pic

A [B, CI, C] D, K

[S, L, T]

//Closed||
500 x 34 x 11 mm

Long Improved Mannheim. Made for Post & H-O only; not sold as Hemmi brand.

Post 1454 (-1936-WWII);
H-O 1772 (-1935-58-)
H-O 341-3235 (-1969-).

WWII-1969

Pic

//Closed||
500 x 40 x 12 mm

Wide Long Improved Mannheim. Hemmi & Post brands.
{Three Hairlines: D: C, C}.

51/1, 51/3

1932-42

Pic

Same as 50/1, 50/3 but with decimal-indicating cursor.

Formerly model 103.

Tamaya 4466, 4467 (1932).

1932-42

Pic

A [B, CI, C] D

[S, L, T]

//Closed||
125 mm x 15/16 x 11/32 in

Thicker than 34R.

Tamaya 4468;
Post 1448 (1936-37).

1932-42

Pic

Same as 52 but with decimal-indicating cursor.

Tamaya 4469 (1932).

1936-42

Pic

A [B, CI, C] D, K
with over-range

[S, L, T]

//Closed||
150 x 26 x 6 mm

"Extra Fine Improved Mannheim" with magnifying cursor.

Post 1453 (c1935-WWII).

1936-42

Same as 54 but without magnifying cursor.

Models 60-79: Rietz Slide Rules ( K, A [B, C] D, L and [S, S&T, T] )

60/1, 60/3

1932-3x

Pic

K, A [B, C] D, L

[S, S&T, T]

//Closed||
250 mm x 1¼ x 13/32 in

Rietz. Single line model 60/1 discontinued ca 1930.

Tamaya 4470, 4471 (1932)

193x-42

Pic

K, A [B, C] D, L
with over-range

61/3

1932-42

Same as 60/3 but with decimal-indicating cursor.

62/3

1932

K, A [B, C] D, L

[S, S&T, T]

//Closed||
150 mm

Extra Fine Rietz.

Tamaya 4472, 4473 (1932)

63/3

1932

Same as 62/3 but with decimal-indicating cursor.

64, 64/1, 64/3

1932-68

Pic

K, A [B, CI, C] D, L
with over-range

[S, S&T, T]

//Closed||
250 x 34
x 11 mm

"System Rietz." {64/3 hairlines: D: C, C} Some w 13-0-13 cm on bottom. Probably without over-range before 1935.

Tamaya 4474 (1932)

64T

1965-71

Pic

K, A [B, BI, CI, C] D, DI, L
with over-range

[T2, T1, ST, S]

//Closed||
250 x 34
x 11 mm

"Super Rietz." {3 hairlines: D: C, C}.

1932-42

Pic

Same as 64/3 but with decimal-indicating cursor.

//Closed||
250 x 34
x 11 mm

Tamaya 4475 (1932)

1932-68

Pic

K, A [B, CI, C] D, L
with over-range

[S, S&T, T]

//Closed||
150 x 26
x 9 mm

Extra Fine Improved Rietz.
{3-line cursor: D: C, C}
Some 8-0-8 cm on bottom.

Tamaya 4476 (1932)

66F

1936-42

Pic

Same as 66 but thin.

1932-42

Same as 66 but with 3-line magnifying cursor.

Tamaya 4477 (1932)

1932-42

Same as 66 but with 3-line decimal-indicating cursor.

Tamaya 4478 (1932)

1932-42

Same as 66 but with 3-line decimal-indicating magnifying cursor.

Tamaya 4479 (1932)

1932-43

Pic

K, A [B, CI, C] D, L
some with over-range

[S, S&T, T]

//Closed||
500 x 34
x 12 mm

Long Improved Rietz.
{3 hairlines: D: C, C}.

Tamaya 4480 (1932)

1951-70

Pic

//Closed||
500 x 40
x 12 mm

1966-71

Pic

K, DF [CF, CIF, CI, C] D, A
with over-range
Folded at √10.

[TI2, TI1, L, SI]

//Closed||
500 x 40
x _ mm

"Precision Slide Rule for Practical Engineers." Single hairline.

1937-EOB

Pic

K. A [B. CI. C] D, L
with over-range

[S, S&T, T]

//Closed||
125 x 26
x 5 mm

Pocket Improved Rietz.
{3 hairlines: D: C, C}.

Models 80-89: "Electro" Slide Rules

80
80/1
80/3

1930-32

Pic

LL2, A [B, CI, C] D, LL3
No over-range

No over-range
[S, L, T]
E, F widely separated in gutter.

//Closed||
250 mm x 1 ¼ in x 10 mm

Electro. LL scales keyed to offset "W" gauge mark. No over-range. Same as model 3 with CI scale added.

Hemmi 3;
Tamaya 4481, 4482 (1932);
H-O 1770 (-1928-c50);
Post 1456 (c1934-WWII)

1932-33

Pic

//Closed||
250 x 34 x 11 mm

Same as preceding but on slightly wider body.

1934-36

Pic

[S, L, T]
E, F close together in gutter

Same as preceding but no "W" gauge mark. E, F close together in gutter.

1936-52

Pic

LL2, A [B, CI, C] D, LL3
with over-range

Same as preceding but with over-range extensions.

81/1, 81/3

1932-42

Pic

Same as 80/1, 80/3 but with decimal-indicating cursor.

Details vary depending upon date of manufacture. See model 80.

Hemmi 4;
Tamaya 4482, 4484 (1932)

1932-37

Same as 80/1 except short.

//Closed||
125 x _
x 9 mm

Tamaya 4485 (1932)

1932-37

Same as 82 but with decimal-indicating cursor.

Tamaya 4486 (1932)

1932

Same as 82 but with magnifying cursor.

Tamaya 4487 (1932)

1932

Pic

Same as 82 but with magnifying decimal-indicating cursor.

Tamaya 4488 (1932)

MIOJ

Pic

db, Neper, A [B, CI, C] D

[TI2, TI1, L, SI1]

//Closed||
250 x 34 x 11 mm

Not electro, therefore model number 85 is inappropriate. {3 hairlines: A: C², 1.307} (Why 1.307?)

Rare.

80K

1953-70

Pic

E, F, A [B, CI, C] D, LL2, LL3
with over-range

[S, L, T]
Bottom Edge: K

//Closed||
250 x 34 x 11 mm

Electro. K scale on bottom edge; no scales in gutter. No hp mark but different cursors avail for British/US and French/Metric HP. {3-line cursor: A: hp, C²}.

86/3

1936-42

LL2, A [B, CI, C] D, LL3
with over-range

[S, L, T]
Gutter: E, F

//Closed||
150 x 26 x 8 mm

"Extra fine Electro." Hp gauge mark. No W mark. E,F scales close together in gutter. {Three hairlines: A: hp, C²}.

87/3

1936-42

Same as 86/3 but with magnifying cursor.

86/3K

1950

Pic

LL2, A [B, CI, C] D, LL3
with over-range

[S, L, T]
Gutter: E, F
Bottom Edge: K

//Closed||
150 x 26 x 8 mm

Same as model 86/3 except K scale added to bottom edge.

1951

Identical to and contemporaneous with model 86/3K.

86K

1954-70

Pic

E, F, A [B, CI, C] D, LL2, LL3
with over-range

[S, L, T]
Bottom Edge: K

//Closed||
150 x 26 x 8 mm

"Extra Fine Electro." No scales in gutter, no hp mark. {Three hairlines: A: hp, C²}.

Models 90-99: Stadia Slide Rules

1932-42

Pic

L, D [M1, M2, C] D, A with over-range

[S, S&T, T]
Bottom Edge: K, IA

//Closed||
250 x 34 x _ mm

Stadia. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to rightmost hairline.

90A

1940

Same as 90

90B

1939?

Pic

Same as 90 but uses "centesimal degrees."
(100 centesimal degrees = right angle)

First of a proposed series (models 90B, 91B, 2690B) of centesimal-degree stadia rules. Models 91B and 2690B were never manufactured.

1932-42

Pic

Same as 90 but with decimal-indicating cursor

Tamaya 4490 (1932)

91A

1939?

Same as 91.

"91A" used to distinguish this rule from proposed centesimal degree model 91B.

1932-42

Pic

L, D [M1, M2, C] D, A

[S, S&T, T]
Bottom Edge: K, IA

//Closed||
150 x 26 x 9.6 mm

"Extra Fine Stadia." Two calculating scales on bottom edge. {3 hairlines: D: C, C}.

Tamaya 4491 (1932)

1932-42

Pic

Same as 92 but with magnifying cursor.

Tamaya 4491 (1932)

1932-42

Same as 92 but with decimal-indicating cursor.

Tamaya 4491 (1932)

1932-42

Same as 92 but with decimal-indicating magnifying cursor

Tamaya 4491 (1932)

1936-43

Pic

L, D [M1, M2, C] D, A
with over-range.

[S, S&T, T]
Bottom Edge: K, IA

//Closed||
500 x 34 x 11 mm

Long version of model 90. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to center hairline.

Model Numbers 100-107 were assigned to new rules developed in 1926-27; all were replaced by modern numbering system about 1930.

100

1926-27

Pic

A [B, CI, C] D

[S, L, T]

//Closed||
250 mm

Short lived.

Tamaya 2790 (1927)

101

1926-27

Pic

Same as 100 but with decimal indicating cursor.

Tamaya 2791 (1927)

102

1926-28

Pic

A [B, CI, C] D, K

[S, L, T]

//Closed||
250 x 28 mm

Improved Mannheim. Model number changed to 50/1 ca 1928.

Tamaya 2792 (1927),
H-O-1771

103

1926-28

Pic

Same as 102 but with decimal-indicating cursor.

Model number changed to 51/1 ca 1928.

Tamaya 2793, (1927)

104

1927

Pic

LL2, A [B, CI, C] D, LL3
No over-range

[S, L, T]
Gutter: E, F

//Closed||
125 mm

"Pocket Electro." LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No over-range. Hp gauge mark.

Hemmi 82;
Tamaya 2994 (1927)

105

1927

Pic

Same as 104 but with decimal-indicating cursor.

Hemmi 83, Tamaya 2995

106

1927

Same as 104 but with magnifying cursor.

Hemmi 84, Tamaya 2996

107

1927

Same as 104 but with magnifying decimal-indicating cursor.

Hemmi 85, Tamaya 2997

Models 100-109: Large Classroom Demonstration Slide Rules

100

1951-68

Pic

DF [CF, CI, C] D, A
Folded at √10.

[TI, L, SI]

Demo
1000 mm

Demonstration version of model 45.

100K

1969-71

Pic

K, DF [CF,CI, C] D, A
Folded at √10

[TI, L, SI]

Demo
1000 mm

Demonstration version of model 45K

101

1951-68

ℓ, A [B, CI, C] D

[S, K, T]
(S keyed to C/D)

Demo
1000 mm

Demonstration version of model 2640.

101A

1967-EOB

Pic

A [B, CI, C] D, K

[S, L, T]
(S keyed to C/D)

Demo
1000 mm

Demonstration version of models 40RK & 43A.

102

1954-68

Pic

CI, C, [D, A]

Blank

Demo
1000 mm

Demonstration version of model 22.

103

1959-EOB

K, DF [CF, CIF, CI, C] D, A
Folded at √10.

[TI1, TI2, L, SI]

Demo
1500 mm

Demonstration version of model 2664S.

104

1959-69

Demo
1000 mm

Demonstration.

107

1969-EOB

LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.

K, A [B, TI1, TI2, SI] D, DI

Demo
1000 mm

Demonstration version of model P253.

108

1971?

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at √10

K, A [B, TI, SI, C] D, DI, L

Demo
1000 mm

Demonstration version of model 254W.

Models 110-129: Specialty Slide Rules

110

1937-MIOJ

Pic

LL2, A [B, CI, C] D, LL3
with over-range

[S, S&T, T]
Bottom Edge: K

//Closed||
250 x 34 x 11 mm

Mechanical /Electrical slide rule. K scale on bottom edge. {Three hairlines: D: C, C}.

120

1939?

Pic

L, K, A [B, CI, S₁, T₁, C] D, S_Θ
with over-range

[LL3, LL3, LL2, LL2, LL1, LL1]
Bottom Edge: G_Θ
(2 scales)

//Closed||
250 x 34 x 11 mm

"MIGHT." Listed without description by Katsunori Kadokura (Chronology of Japanese Hemmi Slide Rules, Journal of the Oughtred Soc, Vol 1, No 2, August 1992). Pictured specimen identified as Model 120 by Yukio Kubota, March 2014.

DP121

1968-69

Pic

LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1

K, A [B, TI₂, TI₁, SI] D, DI

Projection 305 x 182 x 12 mm

Overhead projection rule for model P253. Sold with five masks for obscuring irrelevant scales.

¥10,000 in catalog dated 6911

DP122

1968-69

Pic

K, A, DF [CF, CIF, CI] D, DI, L

K, A, DF [B, TI₂, TI₁, SI, C] D, DI, L

Projection 305 x 182 x 12 mm

Overhead projection rule for models 2662 and 2664S. Sold with five masks for obscuring irrelevant scales.

Models 130-139: Darmstadt Slide Rules (L, K, A [B, CI, C] D, Cos, Sin, Tg and [LL1, LL2, LL3]) and Variants

130

1950-69

Pic

L, K, A [B, CI, C] D, Cos
with over-range

[LL1, LL2, LL3]
Bottom Edge: SIN, tg

//Closed||
250 x 34 x 11 mm

Darmstadt. S and T scales on bottom edge of rule.
{3 hairlines: D: hp-C, C}.

130W

1970-72

Pic

T, K, A [B, BI, CI, C] D, P, S
with over-range

[L, LL0, LL1, LL2, LL3]

//Closed||
250 mm x 1½ x 7/16 in

Advanced Darmstadt. Unique width.
{3 hairlines: A: C², hp-C²}.

135

1959-71

Pic

T, K, A [B, CI, C] D, P, S
with over-range

[L, LL1, LL2, LL3]

//Closed||
125 x 26 x 5 mm

Pocket Darmstadt.
{3 hairlines: D: hp-C, C}.

P135k

2005

Pic

T, K, A [B, CI, C] D, P, S
with over-range

[L, LL1, LL2, LL3]

Closed
200 x 32 x 4.3mm

Darmstadt. Only 250 made. Manufactured by HEMMI in 2005 to specifications of ISRG and Japanese collectors and sold by subscription.

136

1951-68

Pic

L, K, A [B, CI, C] D Cos
with over-range

LL1, LL2, LL3]
Bottom Edge: SIN, tg

//Closed||
150 x 26 x 8 mm

Extra Fine Darmstadt. D scale is labeled "SIN" other scales not labeled.

Models 140-149: Pocket Duplex Slide Rules

140

MIOJ

Pic

DF [CF, CI, C] D, L
Folded at √10.

K, A [B, TI, SI, C] D, DI

Duplex
150 mm x 1 3/16 x ¼ in

Hemmi's first "pocket" duplex. Body is short version of old narrow model 150.

141
P141

1960-EOB

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π

T, S, U, P [Q, c, V, R] A q, n, L

Duplex
125 x 34 x 4 mm

Air conditioning duct design. Bamboo (141) and all-plastic (P141) versions. Same blank as 149. All-plastic version marked "'Carrier' Ductuler" (Toyo Carrier Corp). Some bamboo specimens carry no brand name, some marked "Carrier 50210," others marked "Shin Nippon Kucho." (SNK was spun off from Toyo Carrier in 1969.)

143

1968-69

Pic

P₁, P₂, DF [CF, CIF, CI, C] D, LL (2 scales)
Folded at 360.

A, N [M, £, S/d, C] D, G

Duplex
125 x 34 x 4 mm

"Commerce." N, M have 365 division for dates. £, S/d = pound/ shilling/ pence. G is a set of conversion gauge marks.

Pocket version of model P263.

149

1959-1962

Pic

LL/1. LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π.

L, K, A [B, TI, SI, C] D, LL0, LL/0

Duplex
125 x 34 x 4 mm

"Pocket 259D" but actually closer to 259 with TI, SI instead of T, S, ST. Hemmi name on back of rule. Bare bamboo edges.

149A

1962-EOB

Pic

Same as 149 except celluloid veneer covers edges.

P149A

1976

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π.

L, K, A [B, TI, SI, C] D, LL0, LL/0

Duplex
125 x 36 x 4 mm

All plastic. About 10 mm longer overall and 2 mm wider than bamboo 149A.

Models 150-300: Ten- and Twenty-Inch Duplex and Open Body Slide Rules

150

1925?-1932?

Pic

DF [CF, CIF, C] D
Folded at π.

K, A [B, S, T, CI] D, L

Duplex
250 mm x 1 3/16 x ¼ in

Hemmi's first duplex slide rule. (But Hemmi called models 150, 152, 153 and 154 "Universal," not "duplex.") Copied from K&E 4088-3 whose size it exactly duplicates.

Post 1458 (1931)
Lietz 3054L (before 1932)

1932?-MIOJ

Pic

Duplex
250 mm x 1 5/8 x ¼ in

Standard (1-5/8 inch) width. Replaced by model 250.

Tamaya 4497 (1932)
Post 1458 (1932-WWII)
US Blue 1881 (--1937--)
H O 1765 (1935-MIOJ)

152

1925-48

Pic

K, A [B, CI, C] D, T

Θ, R_θ, P [Q, Q', C] LL3, LL2, LL1

Duplex
250 mm x 1 5/8 x ¼ in

"Electrical Engineer's Universal" (Duplex). Often no model number. Some marked "US Pat 1459857." (Patent issued to O D Parsons in 1923 for P, Q scales.)

Tamaya 4498 (1932); Post 1459 (c1933-WWII); H-O 1766 (-1935-48-); US Blue 1889 (1930s) Lietz (1930s)

153

1931-EOB

Pic

L, K, A [B, CI, C] D, T, G_θ

Θ, R_θ, P, [Q, Q', C] LL3, LL2, LL1

Duplex
250 mm x 1 5/8 x ¼ in

"Electrical Engineer's Universal" (Duplex). Some (c1938) with stator screws on back of rule. US Patent 2079464, May 4, 1937.

Post 1461 (c1933-WWII);
US Blue 1893 (1030s)

154

1925-69

Pic

DF, P', P [Q, CF, CI, S_θ^o] A, D, K
Folded at π.

Sχ, Tχ, T_θ^o [Th, Sh, Sh, C] D, L, χ

Duplex
500 mm x 1¾ x ¼ in

Electrical Engineer's Universal (Duplex) 20". Two cursors. Early production has scale letters eteched on cursor windows.

Tamaya 4499 (1932);
Post 1460 (c1933-WWII)

155

WWII-1951

Pic

K, A, DF [CF, B, CI, C] D, L
Folded at √10.

Sh₁, Sh₂, Th₁ [TI₂, TI₁, SI₁, C] D, DI

Duplex
250 mm x 1 5/8 x ¼ in

"General Engineering with Hyperbolic Scales. " Replaced by model 255.

157

WWII-1950

Pic

K, A, DF [CF, B, CI, C] D, L
Folded at √10.

LL/1, LL/2, LL/3 [TI₂, TI₁, SI₁, C] LL3, LL2, LL1

Duplex
250 mm x 1 5/8 x ¼ in

"General Engineering with Log-Log Scales."

159

1949-52

Pic

T, DF [CF, CIF, CI, C] D, S, ST
Folded at π

LL0, LL00, A [B, K, L, C] LL3, LL2, LL1

Duplex
250 mm x 1 5/8 x ¼ in

Made to specification of F Post Co. Replaced by model 259 ("Expert Mechanical Engineer") c1952.

Post 1462H "POSTRIG"
(c1949 - 53)

160

1951

Pic

Nomogram1(α=0.05), χ2, A [B, CI, C] D, φ, ax

P, F'1 [F'2, a'] A, χ2, ,Nomogram2(α=0.01)

Duplex
250 mm x 72.5 mm

"Inductive Statistics." Almost three inches wide! Stator with nomograms is about 46 mm wide. All-plastic cursor similar to Relay/Ricoh.

165

1953

Pic

"Statistical Sampling." No slide, just many short scales and a cursor.

190

1939-42

Pic

K, A [B, R2, R1, C] D, DI

[SI2, SCI2, SI1, SCI1]
Bottom Edge: L

Closed
250 x 40 x 11 mm

"Precision Stadia." {3 hairlines: D: C, C}.
Left half of SCI1 scale is inverse cos².

200

1936-68

Pic

D6, D5, D4 [C6, C5, C4, C3, C2, C1] D3, D2, D1

DF6, DF5, DF4 [CF6, CF5, CF4, CF3, CF2, CF1] DF3, DF2, DF1
Scales divided at ⁶√10.

Duplex
400 mm x 1¾ x ¼ in

"Precision Duplex." (Originally known as "Ultra Accuracy.") Four digit precision. Scales are divided into six segments, each 400 mm long. Early production has scale labels in green on cursor. U S Patent 2235106A, March 18, 1941.

201

1967-69

Pic

L2.4, L1.3, A2.4, A1.3 [C4, C3, C2, C1] D1, D2, D3, D4

K4, K3, K2, K1 [CF4, CF3, CF2, CF1] DF1, DF2, DF3, DF4
Scales divided at ⁴√10.

Duplex
500 mm x 1¾ x ¼ in

"Sold in Japan." Scales are divided into four segments each 500 mm long. Early production has scale labels in green on cursor.

250

1950-EOB

Pic

DF [CF, CIF, CI, C] D, L
Folded at √10.

K, A [B, TI₂, TI₁, SI] D, DI

Duplex
250 mm x 1 5/8 x ¼ in

"General Engineering and Business." Replaced models 150 and 2600. About a third have anodized black end brackets.

251

1951-58

Pic

L, DF [CF, CIF, CI, C] D, DI
Folded at π.

K, A [B, T, S, ST, C] D, LL3, LL2, LL1

Duplex
250 mm x 1 5/8 x ¼ in

"Mechanical Engineer."

1958-EOB

Pic

L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

K, A [B, T, S, ST, C] D, DI

H-O 1773

P253

1961-EOB

Pic

LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.

K, A [B, TI₂, TI₁, SI] D, DI.
TI divisions= 1/12 degree

Duplex
250 x 41 x 5 mm

Vectolog." Elaborate clamshell case. All-plastic version of model 264. ¥2.400 in catalog 6911.

H-O 1774-00 (-1964);
Geotec 341-3130 (1964+)

P253 Special

1967

Pic

LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.

K, A [B, TI₂, TI₁, SI] D, DI

Marked "P253 Special" and "Vectolog." Only difference from P253 is green CIF scale.

1965

Pic

LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.

K, A [B, TI₂, TI₁, SI] D, DI,√3V.

Marked "P253 Special" and "Vectolog." Short additional scale on back marked "√3V" at left and and "volt" at right end.

254W

1963-68

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at √10.

K, A [B, TI, SI, C] D, DI, L

Duplex
250 mm x 1¾ x ¼ in.

"High School Students". Basis for model 108 demo rule. Equal length stators.

1963-72

Pic

Traditional stators.

254 W-S

1970s

Pic

Same as 254W but folded at π.

Same as 254W.

Only difference from 254W is where front scales are folded.

Only two specimens known. Date codes "RC" (March 1967) and "UB" (Feb 1970)

1969

Pic

Same as 254W. Folded at √10.

L, K, A [B, TI, SI, P] Q, Q', D, DI

With P, Q, and Q' scales

Date code "TC" = March 1969.

1970s

Pic

K, A, [SIN COS, COS², TI, SI, C] D, DI, L

With stadia scales.

Equal stators date = "OC" (Mar 1964); others = "UB" (Feb 1970) or no code.

1971

Pic

K, A [B, TI₂, TI₁, SI, C] D, DI, L

"High School Students." Traditional stators. Hemmi name on back of rule.

1971

Pic

Same as 254W but folded at π.

K, A [B, TI₂, TI₁, SI, C] D, DI, L

Date code "VC" = March 1971

1970s

Pic

KI, K, AI, A [B, S, T, CI, C] D, LdB, P, DI

May set record for number of different inverse scales on one side of a rule.

1965

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, ST, CI, C] D, LL3, LL2, LL1
Folded at π.

KI, K, AI, A [B, S, T, CI, C] D, LdB, P, DI

Equal length stators.

254WN

1972-EOB

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at √10.

LL/0, K, A [B, TI₂, TI₁, SI, C] D, DI, L, LL0

"High School Students." Traditional stators. Hemmi name and model number on back of rule.

254 WN-S

1972

Pic

Same as 254WN except folded at π.

1973

Pic

Same as 254WN. Folded at √10.

L, K, A, [B, TI₂, TI₁, SI, P] Q, Q', D, DI

255

1950-57

Pic

L, K, DF [CF, CIF, CI, C] D, χ, θ
Folded at π.

Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D,LL3,LL2,LL1

Duplex
250 mm x 1¾ x ¼ in

"Expert Electrical Engineer." Replaced model 155.

1958-61

Pic

L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, χ, θ

255D

1961-EOB

Pic

L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, DI, χ, θ

256

1950-68

Pic

L/dB, Neper, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π.

A, Ĺ [Ċ, SI, TI] D, l, F

Duplex
250 mm x 1¾ x ¼ in

Electrical Communications. Ĺ and Ċ scales are about half length.

257

1952-68

Pic

L, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π.

Ch A-M, Ch N-Z, M₁ [M₂, ^oF, ^oC, ^oK, F(t)] Kg/cm², mm Hg, in. Hg Vac., t_ω

Duplex
250 mm x 1¾ x ¼ in

"Chemical Engineer."

Post 1491 (c1957-67);
H-O 1770 (-1958-)

257L

1971-EOB

Pic

L, K, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π.

Ch A-M, Ch N-Z, M₁ [M₂, ^oF, ^oC, ^oK, LM] mm Hg, Kg/cm², in. Hg Vac., t_ω

"Chemical Engineer." Hemmi name on back of rule.

258

1951

Pic

LL0, LL/0, K, DF [CF, CIF, CI, C] D, R₁, R₂, L
Folded at π.

LL/1, LL/2, LL/3 [T T, SecT ST, Cos S, C] D, LL3, LL2, LL1

Duplex
250 mm x 1¾ x ¼ in

VERSALOG Ia. About 30 specimens marked "Hemmi 258" are known. All are also marked "THE FREDERICK POST CO. NO 1460" or "THE HUGHES OWENS CO. LIMITED NO. 1777." Click here for a short history of model 258.

Post 1460 Versalog (1951+);
H-O 1777 Versalog (1951+).
For information about Versalog models Ib and II see the second page of this Catalogue Raisonne.

259

1950-58

Pic

L, K, DF [CF, CIF, CI, C] D, LL0, LL/0
Folded at π.

LL/1, LL/2, LL/3, A [B, T, S, ST, C] D, LL3, LL2, LL1

Duplex
250 mm x 1¾ x ¼ in

"Expert Mechanical Engineer." Replaces model 159.

1958-63

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π

L, K, A [B, T, S, ST, C] D, LL0, LL/0

"Expert Mechanical Engineer." Hemmi name moved to back of rule.

259D

1953-EOB

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π

L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0

259D-S

1970s

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

LL0, LL/0, K, A [B, T, S, ST, C] D, √1, √2, L

260

1964-EOB

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

LL/0, LL0, K, A [B, T, S, ST, C] D, DI, P, L

Duplex
250 mm x 1¾ x ¼ in

"Advanced Engineer." {3 hairlines: A: C², hp-C²} Some rules c1970 have brand and model on bottom edge. Some marked UNIVERSITY on bottom edge. ¥4,800 in catalog 6911.

260 Demo

1964

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

LL/0, LL0, K, A [B, T, S, ST, C] D, DI, P, L

Duplex
1500 mm
x _

Painted wood classroom demonstration rule. Cursor is single wire.

P261

1965-EOB

Pic

LL01, LL02, LL03, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π.

T, ST, K, A [B, BI, CI, C] D, L, P, S

Duplex
250 x 46 x 5 mm

"Advanced Engineer" (Darmstadt). Stators white or pale blue. {4 hairlines on back of cursor. A: C2, hp-C2, D: C}

T-P 1420 (c1971 only)
T-P 44CB-200 (1972+)
Geotec 341-3660

P262

1965-EOB

Pic

LL01, LL02, LL03, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

K, A, R1, R2 [T2, T1, ST, S, C] D, L, LL00, LL0

Duplex
250 x 46 x 5 mm

"Advanced Engineer" (Rietz).

T-P 1422 (c1971 only),
T-P 44CB-220 (1972+)

P263

1964-69

Pic

P₁, P₂, DF [CF, CIF, CI, C] D, LL, LL Folded at 360.

A, N [M, £, S/d, C] D, G

Duplex
250 x 41
x 5 mm

"Commerce." N, M have 365 divisions for dates. £,S/d = pound, shilling/pence. G is a set of conversion gauge marks

Geotec 341-3155 (1967+)
Hemmi 143 is pocket version.

264

1968-EOB

Pic

LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1
Folded at √10

K, A [B, TI₂, TI₁, SI] D, DI.

Duplex
250 mm x 15/8 x ¼ in

Bamboo version of model P253, Vectolog.

264-S

1969

Pic

K, A [B, TI, SI, P] Q, D, DI.

P & Q scales, Single TI scale.

264-M

Pic

K, A [B, TI₂, TI₁, SI] D, DI.

A mis-marked model 264? Only known specimen was sold on Yahoo Japan, June 2018. Photo shows factory marking "264-M."

264-S

1970s

Pic

LL3, LL2, DF [CF, CIF, CI, C] D, LdB, LL1 Folded at √10.

K, A [B, TI₂, TI₁, SI] D, DI, χ, θ

P265

1968-72

Pic

P₁, P₂, DF [CF, CIF, CI, C] D, LL2, LL1 Folded at 360

A, D [G, 0-24, N] M, 0-24

Duplex
250 x 46
x 4 mm

"Business." N, M have 365 divisions for dates. G is a set of conversion gauge marks. Instructions & scale labels in Japanese.

266

1961-EOB

Pic

(LL/3 and LL/1), LL/2, LL2, A [B, BI, CI, C] D, dBL, S, T

X_L, X_C, F, (τ₁ and P), [(τ₂ and Q), L, C, C_z] L, Z, f_o

Duplex
250 mm
x 1¾ x ¼ in

"Electronics." Announced in 1961 but not in Hemmi catalogs until 1966. Early specimens (1962) marked "Developed by SONY." LL/3, LL/1, τ₁, τ₂, P, Q are partial length scales. Also sold as Geotec 341-3550 (1966+)

P267

1971-EOB

Pic

³√-3, ³√-2, ³√-1, DF [CF, CIF, CI, C] D, √-1, √-2, δ(unif.)
Folded at √10

4√-4, 4√-3, 4√-2, 4√-1 [λ_δ(conc), λ_δ(Trape), λ_M, P] Q, L, T, S

Duplex
250 x 46 x 5 mm

"Structural Design."

269

1965-EOB

Pic

L, F, K, A [B, K', CI, C] D, LL3, LL2, LL1

CL, SL, M, TL [R, ST, T, S, C] D, DI, SinCos1, SinCos2

Duplex
250 mm x 1¾ x ¼ in

"Civil Engineer."

P270

1971-EOB

Pic

J, J [T(ºK), Q(m³/s), Q(m³/s)] Hm(m), Q(m³/s), Ht(m)

X, X, Cz, Cmax(PPM) [He(m), Cy, CI, C] D, A, L

Duplex
250 x 46 x 5 mm

"Pollution A." (air quality analysis) 19 scales in black, red and blue.

P271

1974

Pic

x,x_s(g/kgDA), (ice), T_φ,t_φ(ºC) [h_w,h_s(mmhg), CI, C] D, v, v_a(m³/kgDA), t(ºC), t(ºF)

[t(ºC)(ice), t'_2.5, t(ºC)]

Open
250 x 46 x 5 mm

Moist air. There are 13 scales--most with complicated labels.

274

1973-EOB

Pic

L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at √10

K, A [B, TI₂, TI₁, SI, C] D, DI

Duplex
250 mm x 1¾ x ¼ in

Late model general engineering rule with scales folded at √10 and trig scales inverted. Likely sold only in Japan.

274-S

Pic

K, A [B, TI₂, TI₁, SI, C] D, DI, dB

dB, K, A [B, TI₂, TI₁, SI, C] D, DI, χ, ϴ

275

1950-58

Pic

L, K, DF [CF, CIF, CI, C] D, χ, θ
Folded at π.

Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, LL3, LL2, LL1

Duplex
500 mm x 1¾ x ¼ in

20-inch Version of Model 255.

1958-63

Pic

L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, χ, θ

20-inch Version of Model 255. Some with green scale labels on cursor.

275D

1963-69

Pic

L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

Sh₁, Sh₂, Th, A [B, TI₂, TI₁, SI, C] D, DI, χ, θ

20-inch Version of Model 255D. Some with green scale labels on cursor.

279

1950-58

Pic

L, K, DF [CF, CIF, CI, C] D, LL0, LL/0 Folded at π.

LL/1, LL/2, LL/3, A [B, T, S, ST, C] D, LL3, LL2, LL1

Duplex
500 mm x 1¾ x ¼ in

20-inch Version of Model 259. Some with green scale labels on cursor.

1958-63

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.

L, K, A [B, T, S, ST, C] D, LL0, LL/0

279D

1963-69

Pic

LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL Folded at π.

L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0

20-inch Version of Model 259D. Some with green scale labels on cursor.

P280

1959-72

Pic

T, K, A [B, CI, C] D, L, S, ST

[LL1, LL2, LL3]

Open
250 x 46 x 4 mm

"Beginners."

T-P 1414 (c1971 only), 44BB-140 (1972+); Geo 341-3645; Ahrend P280.

280S

1976?

Pic

L, K, A [B, CI, C] D, S, ST, T

cm
[LL1, LL2, LL3]
inches

Open
250 mm

All plastic. Marked "HEMMI, JAPAN, 280S" but probably made by D&P. Only known specimen found in Thailand

Ahrend P281;
Same as Aristo 0903 except back of Aristo slide is blank.

P281

1970-72

Pic

T, K, A [B, CI, C] D, L, S, ST

Blank

Open
250 x 46 x 4 mm

Rietz.

T-P 1410 (c1971 only), 44BB-100 (1972+);
Geo 341-3640

P283

1970-71

Pic

K, A, DF [CF CI, C] D, L, T, S
Folded at π.

[LL1, LL2, LL3]

Open
250 x 46 x 4 mm

Beginners.

Ahrend P283.

Models 300-999: Specialty Slide Rules

300

WWII

Pic

G, E [F, CI, C] D, M

[Blank]

//Closed||
250 x 34 x 8.5 mm

Decimal Calendar Rule. G scale is folded at 365; E & F folded at 3.042 = 365/12. M scale is set of gauge marks for Japanese weights & measures. Japanese language.

301
301A

1954-69

Pic

τ, ω [CI, f, P, C] D, A, db

[θ, θd, g', g]

//Closed||
250 x 34 x 11 mm

Control Engineering. Four cursors! 301A is 301 plus a transparent overlay.

Post 1490 (1957-ca67)

305

1959-70

Pic

TmV/S, ℓ₁ [ℓ₂, m, a] T, v

[N, F, u]

//Closed||
125x26 x _ mm

Acoustic Design. Patents 225936, 225937.

400

1959-68

Pic

Y, A [B, CI, C] D, LL3, LL2, LL1

E_ß, R(AI), Dist, Dose Rate [S, Isotopes (4 scales)] E_v, Pb, Fe, Al

Duplex
250 mm
x 1¾ x ¼ in

Radioisotope Engineering.

401

1966-69

Pic

d, W [Nt, D, MI, M] L

τo, P [d, D, D, Na(δ)] k(P), d

Duplex
250 mm
x 15/8 x ¼ in

"Coiled Spring Rule."

P402

1966-69

Pic

15 scales in black, red, blue and green -- all labeled in Japanese. Only three scales are full length. Scale arrangement and range of variables differs slightly between the two models.

A, DF [CF, CIF, CI, C] LL (2 scales)
Folded at √10.

Duplex
250 x 41 x 5 mm

"Tanabe Corporate Performance Analysis." P402 for manufacturing businesses; P403 for wholesale and retail distributors. Rule and instructions in Japanese.

Click here for an illustrated explanation of models P402 and P403 by Atsushi Tomozawa.

P403

1966-69

Pic

405

1950-68

Pic

C₂F, Al₂O₃ [Fe₂O₃, C₂AF] C₂A, SO₃, CaSO₄

C₂S (A Scale), CaO [SiO₂(for C₃S), Fe₂O₃, SiO₂(for C₂S), SO₃/Al₂O₃] C₃S, C₂S (B Scale)

Duplex
250 mm
x 1¾ x ¼ in

"Cement Composition." Scale labels are chemical symbols, numbers subscripted. No scales are logarithmic. Fe2O3 and SiO2(for C2S) are separate short scales on same line. Accompanying Instruction Manual published by Portland Cement Assoc. Skokie, Ill, May 1959.

410

1959-69

Pic

G₂, G₁, F₂, F₁ [x, F₁G₁] Z₁+Z₂, G', F'

G₂, G₁, F₂, F₁ [x, CI, C] D, A

Duplex
250 mm
x 1¾ x ¼ in

"Involute of Gear Wheel."

451

1969

Pic

Eight specialized scales. Center scales are not full length.

LL/3, LL/2, LL2, A [B, BI, CI, C] D, dBL, S, T

Duplex
250 mm

"Field Intensity."
There are bamboo and all-plastic versions of this rule; both are marked "451." (Not "P451")

P452

1968-72
(For Post)

Pic

LL1, LL2, LL3, CR_DF [T_CF, CIF, %_CI, T_C] R_D, L, in, cm Folded at π

ST, 3n-2_K, 2n-1_A [B, BI, CI, C] D, P, S, T

Duplex
250 x 46 x 4 mm

"Business." Some marked "System H. Kroon." Yellow slide, green brackets. (Post & T-P have blue slide & brackets)

T-P 1426 (c1971 only), 44CB-260 (1972+)

500

1943

125 mm
x _

"For Airplane." ¥8.50 in 1943 price list. No other mention.

640S

1972

Pic

K, DF [CF, CIF, CI, C] D, A, L
Folded at √10.

[STI, TI₂, TI₁, SI, CI]

//Closed||
250 x 45 x 9 mm

Desk Rule. Bamboo between thick plastic

641

1975

Pic

K, A, DF [CF, CIF, B, CI, C] D, DI, L Folded at √10

[STI, TI₂, TI₁, SI, CI]

//Closed||
250 x 45 x 9 mm

Desk Rule. Bamboo between thick plastic.

642T

1973

Pic

K, A [B, BI, CI, C] D, DI, L
with over-range

[T₂, T₁, ST, S]

//Closed||
250 x 45
x 9 mm

Desk version of 64T. Bamboo between thick plastic.
{3 hairlines: D: C, C}.

Ahrend 643T

651

1969

Pic

K, A, DF [CF, CIF, B, CI, C] D, DI, L
Folded at √10.

[TI₂, TI₁, STI, SI, C]

//Closed||
250 mm x 1½ x 7/16 in

Models 1xxx: Circular Slide Rules

1001

1971

Pic

A, D, C, CI, L

Blank

Circular
80 mm

Circular.

Geotec 341-3910

1002

1971

Pic

A, D [C, CI]

Blank

Circular
80 mm

Circular. Less elaborate than 1001.

2600 Series Rules Introduced in 1940 (February 11, 1940 was the 2600th Aniversary of the Founding of Japan)

2600

1940-51

Pic

DF [CF, CI, C] D, L
Folded at √10.

K, A [B, TI₂, TI₁, SI₁] D, DI

Duplex
250 mm
x 15/8 x ¼ in

General Engineering and Business.

2634

1949-EOB

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[TI₂, TI₁, L, SI]

//Closed||
125 x 26
x 5 mm

Pocket 2664.

P2634

Pic

K, DF [CF, CI, C] D, A
Folded at √10.

[TI₂, TI₁, L, SI]

||Closed||
125 mm
x _

2640

1949-68

Pic

ℓ, A [B, CI, C] D

[S, K, T]
(S keyed to C/D)

||Closed||
200 x 28
x 8 mm

Beginners Slide Rule for 50W. Plastic cursor.

2641

Pic

DF [CF, CI, C] D, A
Folded at √10.

Blank

||Closed||
200 x 28
x 8 mm

Beginners Slide Rule for 45 (which, itself, was a beginner's rule). Plastic cursor.

2645

WWII

Pic

DF [CF, CI, C] D, A
Folded at √10.

[TI, L, SI]

Closed
200 x 28 x 8 mm

Essentially identical to model 45 except CI scale is black.

Only one specimen known.

2662

1966-69?

Pic

K, A, DF [CF, CIF, CI, C] D, DI, L
Folded at √10.

[B, TI, SI, C]

//Closed||
250 x 34
x 11 mm

Some with 13-0-13 cm scale on bottom edge.

See Hemmi Catalogue Raisonne 2 for a slide projector version of this rule.

2664

WWII

Pic

K, DF [CF, CI, C] D, A+L
Folded at √10.

[TI₁, TI₂, SI₂, SI₁]

||Closed||
250 x 34
x 9 mm

Wartime construction (bare vertical edges and back) No model number on rule. A+L scale is left half of A scale joined to right half of L scale.

MIOJ

Pic

K, DF [CF, CI, C] D, A Folded at √10.

[TI₂, TI₁, L, SI₁]

//Closed||
250 x 34
x 11 mm

Better quality construction. Full length A scale; L scale replaces SI_2.

1949-58

Pic

K, DF [CF, CI, C] D, A+L Folded at √10.

[TI₁, TI₂, SI₂, SI₁]

A+L scale is left half of A scale joined to right half of L scale.

2664S

1958-69

Pic

K, DF [CF, CIF, CI, C] D, A Folded at √10.

[TI₂, TI₁, L, SI]

//Closed||
250 x 34
x 11 mm

Same as 2664 except 10 mm longer overall and green CIF scale added.

¥2,200 in catalog dated 6911

2664S-S

1967

Pic

K, A, DF [CF, CIF, CI, C] D, DI
Folded at √10

[TI₂, TI₁, L, SI]

//Closed||
250 x 34
x 11 mm

Same as 2664S except DI scale added.

2670

MIOJ

Pic

K, A [B, CI, C] D, L

[S, S&T, T]

//Closed||
500 x 40
x 12 mm

Long Rietz. Short-lived replacement for model 70. {3 hairlines: D: C, C}.

2690

1951-68

Pic

L, D [M1, M2, C] D, A

[S, S&T, T]

//Closed||
250 x 34
x 11 mm

Stadia. {3 hairlines: D: C, C}.

2690A

1954-55

Same as 2690

"2690A" marked on case to distinguish model 2690 from proposed centesimal degree model 2690B. Rules are marked just "2690."

Odds and Ends

P3526

1970s?

Pic

S, K, A [B, CI, C] D, L, T

None

||Closed||
250 x 40
x 3 mm

Beginner's all-plastic slide rule marked "HEMMI, Japan, NO P3526" but manufactured by Hope Slide Rule Mfg Co, Tokyo. Same as Hope model 51. (The only known 'Hemmi' example was found in New Zealand.)

Hemmi Slide Rule Catalogue Part I Raisonné by Paul Ross

Hemmi Slide Rule Catalogue Part I
Raisonné by Paul Ross