
History: AcuRule, AcuMath, (and later Sterling Plastics) slide
rules were made originally by Festus Mfg. Co., Festus, Missouri, in 1938 by Paul
Jones. The Festus Mfg. Co. and the AcuRule Mfg. Co. filled an important need during the Depression years of 1938 to 1940 and during WWII as a supplier of a low cost, student grade, wood slide rule as well as providing production capacity for
other brand names, such as Dietzgen and Frederick Post. In 1939 the company was renamed AcuRule Mfg. Co., producing slide rules branded as Acurule and Acumath. They later moved to
Saint Louis, Missouri. then moved to in Mt. Olive, Illinois in 1954. AcuMath
became the standard brand of AcuRule, which was retained when merged later as the AcuMath
Division of Sterling Plastics in Mountainside,
New Jersey in 1968. AcuRule Manufacturing was dissolved in 1969. Sterling was subsequently purchased and became a division of Borden Chemical Co. in 1970. Slide rules were produced up
until 1972. Construction: The first slide rules were paper scales glued to a wood stock. Painted (silkscreened) scales followed and vinyl laminated to a wood stock occurred after that. After making wood slide rules since 1938 and dealing with the raw material shortages and allocations during World War II, the AcuRule Mfg. Co. was ready to develop new products. Magnesium core slide rules were produced in 1946 and then vinyl slide rules around 1948. After a few unsuccessful tries their final choice of a substrate was a material consisting of eight layers of a special, 0.015 inch thick, vinyl film laminated with an adhesive under heat and pressure made by the Bakelite Company of Ottawa, Illinois. It was sold in a 30 inch by 20 inch piece that was 0.12 inches thick.
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History researched by George Keane of Festus, Missouri, an associate of ISRM. 
S527 Festus  Lucite Cursor 
Festus  Lucite Cursor  c1938 Made in USA by Festus Mfg, Festus, MO.  Paper on wood scales Front Scale 10in // A [ B, CI, C ] D, K  25cm Back scale: [S, L, T ] Back: equivalents  Paper glued on wood Note: Same stock as AcuRule 100, except paper scales 

REF AcuRule 10J 
Acurule 10J  c1939 Made in USA by Festus Mfg in Festus, MO Front Scale A [ B, CI, C ] D, K Back Slider: Blank Back: Conversion Chart, 25cm Archive  Tom Dilatush Collection 

S343 Festus (preAcuRule 100) 
Festus (preAcuRule 100) Magnifying Cursor 
c1939 Made in USA by Festus Mfg., Festus, MO. Front Scale A [ B, CI, C ] D, K Back scale: 25cm [S, L, T ] 10in Back: equivalents Note: Same scales as AcuRule 100, except no beveled edge 

S289 AcuRule 10D 
Acurule 10D  Magnifier c1938 Made in USA by Festus Mfg in Festus, MO Front Scale A [ B, CI, C ] D, K Back Slider: Blank Back: Conversion Chart 

AcuRule No.10D Magnifying Cursor Student Slide Rule ISRM 14.07.02.54 
AcuRule No.10D Magnifying Cursor  Student Slide Rule c1938 Made in USA by Festus Mfg. Note: "AcuRule" not present on stock. White painted with black scales. 1938 Catalog description: A 10 inch white faced slide rule with "Lucite" Magnifying indicator. Has A, B, C, D, CI and K scales. In cardboard case. MODEL 10D...35c EACH Front Scale 10inch // A [ B, CI, C ] D, K Back Slide (need to flip over and use with C scale): [ S, L, T ] Back: 25 Cm, Conversion Chart Gift Of Ed Millis, Dallas, Texas. Original Owner (marked in well): Christine Whitmore, home: 36 S. Denny St., Indianapolis, IN Phone: FL 77912. This is the home where Christine, a student, used this slide rule for her homework. Its a duplex home #36 is on the right. 

P260 AcuRule 5J Pocket 
AcuRule 5J Pocket  Wood  c1940 Made in USA by Festus Mfg., Festus, MO. Front Scale A [ B, CI, C ] D, K Back Slider: Blank Back: 13Cm, 5 in Back Adv: Security Engineering Co. 

AcuRule Model 50 ISRM 14.07.02.98 
AcuRule 50 c1939 Made in USA by Festus Mfg. Note: "AcuRule" on left of wood stock. White painted with black scales. 1938 Catalog description: A 10 inch white faced slide rule in brown leatherette case. Has a flat "Lucite" indicator. In addition to the A, B, C, D, CI and K scales it has a metric and English linear scale. MODEL 50 ......50c EACH Front Scale 10inch // A [ B, CI, C ] D, K Back Scale: 25 Cm [ S, L, T ] Back: Conversion Chart Gift Of Ed Millis, Dallas, Texas. 

AcuRule Universal ISRM 14.07.02.49 
AcuRule Universal c1940 Made in USA by AcuRule MFg. Co, Formerly Festus Mfg. Note: no "AcuRule" on stock. Intended for rebranding to OEMs. Laminated scales with double bevel. Identical to Frederick Post 1452D Universal. Front Scale: 10inch // A [ B, CI, C ] D, K \\ 25cm Back Scale: [ S, L, T ] Back: Equivalents, Fraction to decimal. Gift Of Ed Millis, Dallas, Texas. 

S050 AcuRule 100 
AcuRule 100  Wood  c1939 Made in USA by Festus Mfg. Front Scale 10 Inch // A [ B, CI, C ] D, K Back Scale: 25 Cm [ S, L, T ] Back: Conversion Chart 

REF Acumath AREL GW Photo SR 
Acumath AREL GW Photo SR  1946 Made in USA  Wood Stock, brass stiffener, Plastic Laminate, Molded cursor Front Scale F, WESTON, ASA [ Daylight, LIGHT, SKY TYPE, SUBJECT, FILTER, GAMMA] DEPTH of FOCUS Back: Film Speed Indexs Archive  George Keane Collection Instructions 3.31MB 

REF Acumath No. 4 White 
Acumath No. 4 White c1965 Made in USA  Note: Stock is only 28mm wide  Magnifying cursor Front Scale K, A [ B, CI, C ] D, L Back Scale: Blank Archive  George Keane Collection 1965 Ad, Plastic Clamshell Case Logo 

Acumath No. 4T Sight Saver Yellow Specimen Needed 
Acumath 4T Sight Saver Yellow c1965 Made in USA  Note: Stock is only 28mm wide  Magnifying cursor Front Scale K, A [ B, CI, C ] D, L Back Scale: Blank > 

P114 Acumath 12 pocket 
Acumath 12  c1965 Made in USA  Note: This is the ONLY yellow AcuMath I've seen Front Scale K, A [ B, CI, C ] D, L Back Scale [ S, T ] 


Acumath Pocket Duplex Mannheim 19491952 Made in USA by AcuDesign. Based on W.J. Boos U.S. Patent 2,594,857  Apr 29, 1952 Note: All Vinyl Stock, otherwise identical appearance and construction as CharvozRoos PSR101 which has a celluloid laminated wood stock. Has fixed rear hairline for trig scales. Front Scale: A [ B, CI, C ] D, K Back Scale: Equivalents [ S, L, T ] Equivalents Donated by Daniel Swerdlow, Bethesda, Maryland Daniel Swerdlow is a secondgeneration engineer from New York City and has degrees in electrical engineering from New York University and Michigan State University. He has done telecommunications engineering for major corporations and currently lives in the Washington, DC area and works at the United States Patent and Trademark Office. Dan has gifted most of his collection to ISRM to support the museum. Many specimens may be found in the various ISRM galleries. 

AcuMath No. A51 Duplex Mannheim (Boos Patent) ISRM 13.07.03.04 
Acumath No. A51 Duplex Mannheim 19491952 Made in USA by AcuDesign. Based on W.J. Boos U.S. Patent 2,594,857  Apr 29, 1952 Note: Magnesium and Vinyl Stock with finger pockets in slide. Similar to wood version of Charvos Roos 105D. Has fixed rear hairline for trig scales. Front Scale: A [ B, CI, C ] D, K Back Scale: Equivalents [ S, L, T ] Equivalents Original owner's initials on stock: 'L.H.' Donated by Daniel Swerdlow, Bethesda, Maryland 

REF Acumath A60 Log Log Decimal Trig 
Acumath A60 Log Log Decimal Trig  c 1945 Made in USA by Acu Design (ST. Louis) Note: Early Vinyl clad Magnesium with finger pocket Front Scale T, DF [ CF, CIF, CI, C ] D, S Cos, ST Back Scale LL0, LL00, A [ B, K, L, C ] LL3, LL2, LL1 Archive  Tom Dilatush Collection 

REF Acumath A80 
Acumath A80  c 1945 Made in USA by Acu Design (ST. Louis) Note: Early Vinyl clad Magnesium with finger pocket Front Scale K, A [ B, S, T, C ] D, S, DI Back Scale: Note Folded scales Equivalents, [ L, C2, C1 ] D1, D2, D Archive  Tom Dilatush Collection 

S241 Acumath 90 Mannheim 
Acumath 90 Mannheim  c1945 Made in USA  Acu Design  Early Magnesium with finger pocket Front Scale T, DF, A [ CF, CIF, CI, C ] D, S, ST Back Scale Equivalents [ B, K, L, C ] Equivalents 

Acumath 90A Mannheim Trig ISRM 13.06.25.02 
Acumath 90A Mannheim Trig  c 1945 Made in USA by Acu Design (ST. Louis) Early Magnesium with finger pocket Front Scale T, DF [ CF, CIF, CI, C ] D, S Cos, ST Back Scale Equivalents, A [ B, K, L, C ] Equivalents Gifted by Norma Tanner of Libertyville, Illinois 

Acumath 130 Log Log Decimal Trig ISRM 11.11.17.07 
Acumath 130 Log Log Decimal Trig  c 1945 Made in USA by Acu Design (ST. Louis) Early Magnesium with finger pocket Front Scale LL0, LL00,A [ B, K, CI, C ] D, S Cos, ST Back Scale L, LL1, DF [ CF, CIF, CI, C ] D, LL3, LL2 

Acumath 150 Duplex Log Log Decimal Trig ISRM 11.11.17.06 
Acumath 150  Duplex Log Log Decimal Trig  pre 1968 Made in USA by Acumath  no logo Front Scale LL01, K, A [ B, T, ST, S ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 

S168 Acumath 150 Duplex Log Log Decimal Trig 
Acumath 150  Duplex Log Log Decimal Trig  c1968 Made in USA b y Acumath  Oval Acumath Logo Front Scale LL01, K, A [ B, T, ST, S ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 

Acumath 400 Mannheim ISRM 11.11.17.04 
Acumath 400 Mannheim  c1968 Made in USA  Grooved stock, Thin Cursor, No Logo Front Scale S, K, A [ B, CI, C ] D, L, T Back Blank 

Acumath 400 ISRM 11.02.14.01 
Acumath 400  Simplex Trig  c1968 Made in USA  note round corners, no Logo Front Scale S, K, A [ B, CI, C ] D, L, T Back Blank Donated by William (Bill) Mulroy who used this in High School in Italy where his dad was stationed in 1965. Bill joined the US Army and served in Vietnam. He later owned a concrete contracting company in Colorado. Packaging gift of Ed Millis, Dallas, Texas. 

Acumath 400 ISRM 13.06.25.04

Acumath 400  Simplex Trig  c1968 Made in USA by Sterling Plastics  note round corners, wrap over cursor  Oval Logo Front Scale S, K, A [ B, CI, C ] D, L, T Back Blank Gifted by Norma Tanner of Libertyville, Illinois Norma has been a participant of the ISRM Slide Rule Loaner Program. In addition, she had her own collection that she loaned out to students. This one is part of the collection sent to ISRM. Norma writes: "After teaching math and/or science for 24 years, I am now enjoying retired life. Having been educated at MIchigan State University during a time when using a slide rule was the only technology available for advanced calculations, I decided to create a unit of study for my students that would introduce them to the slide rule. My goals were for students to strengthen their ability to estimate and use scientific notation, as well as to discover the historic significance of the slide rule. While it was hard for them to put aside their electronic calculators, they were fascinated, engaged, and thrilled when they could multiply 2 x 3 and actually get 6 instead of 5.9. In the end my students were happy to be reunited with their calculators, but had a new appreciation for the value of estimating, scientific notation, and accuracy in measurement. Goals met! " 

Acumath 400 (wide Stock) ISRM 13.06.20.07 
Acumath 400  Simplex Trig  c1968 Made in USA by Sterling Plastics  wide stock, square corners, wrap over cursor  Oval Logo Front Scale S, K, A [ B, CI, C ] D, L, T Back Blank Gifted by Phillip Rodley, Upper Hutt, New Zealand 

Acumath 400B ISRM 13.06.25.14 
Acumath 400B  Simplex Trig  c1965 Made in USA  Oval Logo, Narrow Stock, Rounded Braces, Wrap Over Cursor Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Gifted by Norma Tanner of Libertyville, Illinois 

Acumath 400B (wide Stock) ISRM 13.06.25.13 
Acumath 400B  Simplex Trig  c1968 Made in USA  Oval Logo, Wide Stock, Square Braces, Wrap Over Cursor Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Gifted by Norma Tanner of Libertyville, Illinois 

Acumath 401 Student Mannheim Trig ISRM 15.01.05.01 
Acumath 401 Student Mannheim Trig Made in USA  Oval Logo, Narrow Stock, rounded Braces, Wrap Over Cursor Front Scale K, A [ B, T Cot, ST, S Cos, C ] D, DI Back: Blank Gifted by George Keene, Festus, Missouri. 

Acumath 500 ISRM 11.11.17.05 
Acumath 500  Simplex Trig  1960 Made in USA by Acumath  No Logo Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Conversion Table 

Acumath 500 Trig ISRM 14.07.02.50 
Acumath 500  Simplex Trig  1960 Made in USA by Acumath  Oval Logo Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Gifted by Ed Millis, Dallas, Texas. 

Acumath 500 (Square Braces) ISRM 12.06.24.65 
Acumath 500  Square Braces  c1968 Made in USA  Note: Braces made of thin folded sheet metal Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Gift of Huang Collection 

S447 Acumath 511 Student Mannheim 
Acumath 511 Student Mannheim c 1945 Made in USA  Early Magnesium with finger pocket Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties 

AcuMath 511 Mannheim Professional ISRM 13.06.25.01 
AcuMath 511 Mannheim Professional c1960 Made in USA  Note: Stock/Slide has a plastic laminate over alloy substrate. Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Gifted by Norma Tanner of Libertyville, Illinois 

S224 AcuMath 511 Professional Mannheim 
AcuMath 511 Professional Mannheim  c1955 Made in USA  Note: this has a painted allmetal stock and a single sided cursor to reduce manufacturing cost. The cursor is retained by grooves on the stock. Front Scale S, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties 

REF Acumath 550 
Acumath 550  Professional Mannheim Trig c1960 Made in USA by AcuRule Front Scale K, A [ B, T Cot, ST, S Cos] D, DI, L Back Scale Conversions, DF [ CF, CIF, CI, C ] D, Conversions, con't. Archive  Tom Dilatush Collection 

S427 Acumath 600 Basic Trig 
Acumath 600 Basic Trig  c1955 Made in USA Front Scale S, S&T, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties 

Acumath 600 Basic Trig ISRM 14.07.02.53 
Acumath 600 Basic Trig  1955 note: double end plates simplex cursor  all plastic stock Made in USA by Acumath  No Acumath Logo Front Scale S, S&T, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Original owner (Written in sleeve): Chareles Middleton, "Don't steal Me! My owner is flinking chemistry". Southeaster, Texas A&M. Gift of Ed Millis, Dallas, Texas. 

Acumath 600 Basic Trig ISRM 
Acumath 600 Basic Trig  1955 note: double end plates simplex cursor  grooved edge plastic stock (needed for onesided cursor) Made in USA by Acumath  Oval Acumath Logo Front Scale S, S&T, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties 

Acumath 600 Basic Trig Yellow Stock REF 
Acumath 600 Basic Trig Yellow Stock  c1959 Note: double end plates Duplex cursor Made in USA by Acumath  Oval Acumath Logo Front Scale S, S&T, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties Archive  Herman van Herwijnen's Slide Rule Catalogue at ISRM. 

FullertonAcu 600 Basic Trig ISRM 12.06.24.31 
FullertonAcumath 600 Basic Trig  1959 note: double end plates duplex cursor  flat edge plastic stock Made in USA by Acumath for Fullerton  Oval Acumath Logo Front Scale S, S&T, K, A [ B, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties 

S138 Acumath 600 
Acumath 600  Simplex Trig  c1968 Made in USA Front Scale K, A [ B, S, ST, CI, C ] D, L, T Back Scale Conversion Table [Fraction=Decimal] Trig properties 

S522 AcuRule MR700 MuStick Chord/note transposition 
AcuRule MR700 MuStick  Key transposition  c1965 Made in USA  Distributed by Mel McSwain Co. Front Scale Original Key [ Transposed Key ] Diminished/Augmented Back: Blank 

S418 Acumath 800 AccuLine 
Acumath 800 AccuLine  c1968 Made in USA Front Scale LL01, K, A [ B, T Cot, ST, S Cos] D, DI, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 Note: Adjustable cursor alignment 

Acumath 900 Professional Mannheim Trig ISRM 14.07.02.51 
Acumath 900  Professional Mannheim Trig  c1955 Made in USA  Note: metal ends both sides Front Scale K, A [ B, T Cot, ST, S Cos] D, DI, L Back Scale Conversions, DF [ CF, CIF, CI, C ] D, Conversions, con't. Gift of Ed Millis, Dallas, Texas. 

S047 Acumath 900 
Acumath 900  Professional Mannheim Trig  c1960 Made in USA  Note metal ends only on one side Front Scale K, A [ B, T Cot, ST, S Cos] D, DI, L Back Scale Conversions, DF [ CF, CIF, CI, C ] D, Conversions, con't. 

Acumath 1200 ISRM 
Acumath 1200  Pocket Simplex  c1965 Made in USA Front Scale K, A [ B, CI, C ] D, L Back Scale [ S, T ] 

P065 Acumath 1200 
Acumath 1200  Pocket Simplex  c1965 Made in USA  Note: Black End pieces, NIB Front Scale K, A [ B, CI, C ] D, L Back Scale [ S, T ] 

P005 FullertonAcu 1200 
FullertonAcu 1200  Pocket Simplex  c1965 Made in USA Front Scale K, A [ B, CI, C ] D, L Back Scale [ S, T ] 

P229 AcuMath 1211 Pocket  Pre AcuMath Logo 
AcuMath 1211  Pocket duplex  c1965 Made in USA  Vinyl laminate on Magnesium Stock, Metal braces Front Scale K, A [ B, CI, C ] D, L Back Scale [ S, T ] Multilined cursor 


AcuMath 1211 Student Mannheim 5 inch Pocket Duplex  c1955 Made in USA by AcuRule Mfg. Co. Box 142, Mt. Olive, Illinois Note: Oval logo, Magnesium and Vinyl stock, Engraved, Metal Braces Front Scale: K, A [ B, CI, C ] D, L Back Scale: [ S, T ] Multilined cursor Back advertisementAndersonCrane Company, Minneapolis, Minn. Note: Retail box with 44P instruction booklet. Gifted by Maureen White of Minneapolis, Minnissota, neice of Phillip Murray This slide rule, was owned and used by Phillip C. Murray (19202008) in his career. Phil attended Culver Military Academy in Indiana then received his degree in engineering from Purdue University, class of 1942 (Phi Delta Theta). He served in the U.S. Army from 19421946 and later employed by Pillsbury as a mechanical engineer. He traveled around the world helping to set up operational facitlies for the company. Phil was a lifelong member of Purdue's Phi Delt and was a significant donor and loyal supporter of their annual fund and educational foundation for many years. Phil was a gifted storyteller, avid bowler and spent his later years volunteering for Habitat for Humanity. 

AcuMath 1240 (White Braces) ISRM 
AcuMath 1240  c1965 Made in USA Front Scale K, A [ B, CI, C ] D, L Back Scale: None Note: In red/clear plastic case w/ manual No44P 

AcuMath 1240 (Black Braces) ISRM 
AcuMath 1240  c1965 Made in USA Front Scale K, A [ B, CI, C ] D, L Back Scale: None In Retail Box w/sheath w/manual No44 

S097 Acumath 1300 
Acumath 1300  Duplex Log Log Decimal Trig c1960 Made in USA Front Scale LL01, K, A [ B, T Cot, ST, S Cos ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 

S398 Acumath 1311 Log Log Decimal Trig 
Acumath 1311  Duplex Log Log Decimal Trig c1945 Made in USA  Note: Finger detents on slide Front Scale LL01, K, A [ B, T Cot, ST, S Cos ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 Early Magnesium Model  narrow cursor 

Acumath 1311 Log Log Decimal Trig ISRM 13.07.03.01 
Acumath 1311  Duplex Log Log Decimal Trig Made in USA by AcuMath.C1955 Note: Braces on both sides, Magnesium and Vinyl Stock Front Scale LL01, K, A [ B, T Cot, ST, S Cos ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 Gifted by Daniel Swerdlow of Bethesda, Maryland 

Acumath 1311 Log Log Decimal Trig ISRM 14.07.02.52 
Acumath 1311  Duplex Log Log Decimal Trigc1950 Made in USA  Note: Braces only on one side Front Scale LL01, K, A [ B, T Cot, ST, S Cos ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 Gifted by Ed Millis, Dallas, Texas. Reference (S134) with more readable printing. 

AcuMath 1500 Log Log Decimal Trig ISRM 15.04.17.02 
AcuMath 1500 Log Log Decimal Trig c1965 Made in USA  marked with "U.S." (Government issue) Note rounded braces. Same scales as 1311 but no red inverse scale markings Front Scale LL01, K, A [ B, T, ST, S ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 Gifted by Jay Wright of Washington D.C. Jay Kelly Wright, who owned this slide rule (1 of 2), was born in Washington D.C. He used them while a student at WashingtonLee High School, Arlington, Virginia from 19591961. After graduation from Dartmouth College in 1965, he served in the United States Navy from 19651969. He attended Harvard Law School and is a lawyer in the Washington D.C. area. 

S135 Acumath 1500 
Acumath 1500  Duplex Log Log Decimal Trig  c1968 Made in USA Note square braces. Same scales as 1311 but no red inverse scale markings Front Scale LL01, K, A [ B, T, ST, S ] D, L, LL1 Back Scale LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2 

S400 Acumath C.V. Ore  No. 1155

Acumath C.V. Ore  SM No. 1155 Made in USA by AcuRule Co. for C.V. Ore, Harvey, Illinois  1955 Front Scale: DS [ CI, C ] DM Back Scale: Blank See the Lawrence/Engineering Instruments gallery for the first wooden version. Mr. C. V. Ore of Harvey, Illinois describes his slide rule, which first sold for $1.50 in 1956, made by Engineering Instruments, as follows: "The SM Slide Rule is a simplified, multipurpose calculating instrument designed especially for the beginner. It contains the basic scales of professional slide rules ( C, D, CI ) as used by engineers for 80 to 90 percent of their work. And in addition to the basic scales the SM Slide Rule has two special purpose scales for teaching the beginner the mechanics of the slide rule and to aid him in reading conventional C, D, and CI scales." 

S475 Connecticut Spring Corp Spring Design 
Connecticut Spring Corp Spring Design  c1945 Made by AcuRule for Connecticut Spring, Hartford, CT. Magnesium stock Front Scale Wire Size [ Wire Size, Load, Ratio D/d, Rect: ratio b/t ] Lbs per Inch Deflection Back Scale Mean Dia [ Mean Dia, Active coils, G, Rect: ratio b/t ] Stress Archive  Billy Guthrie collection Instructions 3.31MB 

Connecticut Spring Corp Spring DesignISRM 05.03.10.01 
Connecticut Spring Corp Spring Design  c1955 Made by AcuRule for Connecticut Spring, Hartford, CT. All plastic stock Front Scale (Step 1 design spring force) Wire Size [ Mean Dia., Active Coils, Rect: ratio b/t ] Lbs per Inch Deflection Back Scale (Step 2  determine design stress) Mean Dia [ Wires Size, Load, Ratio: D/d, Rect: ratio b/t ] Stress Note: Compare spring design scales with the Pickett ASC slide rules and manuals. Instructions 3.31MB 

MidContinent Spring Co. Spring Design Slide Rule ISRM 14.10.17.01 
MidContinent Spring Co. Spring Design Slide Rule c1950 Made by AcuRule for MidContinent Spring Co. St. Louis, Missouri. All plastic stock Front Scale (Step 1 design spring force) Wire Size [ Wires Size, Load, Ratio: D/d, Rect: ratio b/t ] Lbs per Inch Deflection Back Scale (Step 2  determine design stress) Mean Dia [ Mean Dia., Active Coils, Rect: ratio b/t ] Stress Note: Compare spring design scales with the Pickett ASC slide rules and Connecticut Spring Corp manuals. 
Frederick Post 1452D Universal c1945 ISRM 14.07.02.48 
Frederick Post 1452D Universal Made in U.S.A by AcuRule Mfg. Festus, Missouri. Front Scale: 10in // A [ B, CI, C ] D, K \\ 25cm Back Scale: [ S, L, T ] Back: Conversion/Geometry Chart Gift Of Ed Millis, Dallas, Texas. 
S442 Dietzgen 1757 Primatrig 
Dietzgen 1757 Primatrig  c1955 Made in USA by AcuRule for Dietzgen  All Plastic Stock/slide, metal ends. Similar to (S427) AcuMath 600 Basic Trig Front Scale L, K, A [ B, CI, C ] D, T Cot, ST, S Cos Rear Scale Trig Identities [ Decimal to Fractions ] Equivalents Same as S427 AcuMath 600 Basic Trig (scales rearranged) 
This Demo slide rule is basically identical to the Laboratory Specialties Demonstration Slide Rule of 1939. shown in the sheet on the left. Laboratory Specialties sold AcuRule slide rules and AcuRule may have been commissioned to make this item. 
AcuRule (1939) and AcuMath (1961) Catalog Spec sheets2.27MB 