Concise 600 Science Tables and Circular Slide Rule

This white plastic circular slide rule is on a rectangular base that has a 4-inch ruler on the left side and a 10-cm ruler on the right. A black plastic tape attached along the top edge reads: MATLACK. The top of the base is marked: CONCISE (/) SCIENCE TABLES (/) AND CIRCULAR SLIDE RULE. The slide rule has a D scale along the outer rim. A rotating disc fastened with a metal grommet has C, CI, L, A, S, T, and K scales. There is a clear plastic rotating indicator, which is labeled in red with the letters for the scales. The bottom of the base is marked: BY SAMA & ETANI.
The back of the instrument has a chart for converting temperatures from Celsius to Fahrenheit and a periodic table of the chemical elements. The bottom right corner of the back is marked: © 1968 CONCISE INTERNATIONAL CO. LTD. The left edge is marked: DESIGNED BY SAMA & ETANI, INC., GROTON, MASSACHUSETTS 01450, U.S.A. (/) MADE IN JAPAN BY CONCISE MODEL 600.
A rectangular plastic card fits inside a slot in the base. The card provides various conversion tables for energy, power, the Greek alphabet, velocity, volume, mass, force, length, and area. This side of the card is printed so that the card can be pushed out halfway from either side of the base, and the printed tables will appear right-side-up. The back of the card has tables for gas constant values and pressure, along with lists of mathematical formulas and chemical and physical data. One edge of the card is marked: ©1968 CONCISE INTERNATIONAL CO., LTD. INSERT - ST.
The instrument fits in a rectangular black plastic case. There is no instruction manual, but the instrument likely was originally accompanied by a copy of: Sama & Etani, Reference Tables and Circular Slide Rule (Groton, Mass., 1969),
The donor, Glenn Matlack, purchased this slide rule in the fall of 1968 for his junior high school general science course at Tower Hill School in Wilmington, Del. Sama & Etani designed and distributed several slide rules made by Concise. For other slide rules by Concise and the company history, see 1985.0636.02, 1996.0141.01, and 2003.0012.01.
Reference: Accession file.
Currently not on view
Object Name
calculating rule
slide rule
date made
Physical Description
plastic (overall material)
overall: .2 cm x 8.8 cm x 11.4 cm; 3/32 in x 3 15/32 in x 4 1/2 in
place made
Nihon: Kanto, Tōkyō
ID Number
accession number
catalog number
Rule, Calculating
Conversion Chart
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Slide Rules
Data Source
National Museum of American History, Kenneth E. Behring Center


"I have been carrying my Concise 600 circular slide rule in my breast pocket on a daily basis, seven days a week, for over 40 years. It is in its original, white, soft-plastic, slip-case (perhaps vinyl) along with the original instruction booklet, "Reference Tables and Circular Slide Rule " (Sama and Etani, Inc., Groton, Mass., 1969), A note inside the cover page warns: "The distortion temperature of the vinyl construction material is 150 [degrees] F; therefore, exposure of the instrument to such temperatures should be avoided. " Your picture of the slide rule and its data card does not take advantage of a feature that can be useful to frequent users. Note a tiny open star in the upper left-hand corner of the rule, just above the 4-in. mark. If you look at the data card you should find one corner that has a matching star. The idea is always to insert the data card into its holder with the two stars matching, so that once you become familiar with the card you will know where to look for your data of interest without having to flip the card over and around hunting for what you want. Another feature is the combination of plastic construction with all characters and lines engraved. This combination allows for washing "...with lukewarm water and mild soap. " I use the data card fairly often and the slide rule once-in-while. What more can I say, I'm a chemical engineer."
"Wow! I have one of these, which was given to me by my dad, who got it from a coworker. I never knew I had an actual artifact!"

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