Impact Metric Converter Slide Rule for Regal Beloit

Around 1970 many American companies and government agencies encouraged Americans to adopt the metric system. Regal Beloit of Wisconsin and other manufacturers of cutting tools and gear boxes adopted the units of measure and distributed devices like this one to assist in their use.
The one-sided white cardboard rule is printed in orange and black and has eight windows. Two logarithmic scales on the slide are viewed through four of the windows so that the user can convert between yards or feet and meters; centimeters and inches; pounds and kilograms; and tons and metric tons. Two more logarithmic scales on the slide permit conversions between square yards and square meters; square centimeters and square inches; cubic yards and cubic meters; and liters and imperial gallons or U.S. gallons. Below the windows is a scale for converting between Celsius and Fahrenheit temperatures. The rule is marked: REGAL BELOIT. It is also marked metric/inch (/) CONVERTER. It is also marked SWANI PUBLISHING COMPANY (/) P.O. Box 284 • Roscoe, Illinois 61073 (/) 815 / 389-3065.
The back of the rule has small windows for reading conversions between fractional inches, decimal inches, and millimeters from columns of numbers printed on the slide. Tables of equivalents appear above more windows for reading conversions between inches and centimeters and miles and kilometers. After another table of prefixes and equivalents, instructions for using this side of the rule are provided. More small windows permit conversions between U.S. gallons and liters and cubic feet and cubic meters. At the bottom, the rule is marked: DISTRIBUTED BY (/) C-6862. The back of the slide is marked ©1971, IMPACT, Culver City, Callf. (/) Printed in U.S.A.
Impact was presumably a printing company. Swani was a division of Regal Beloit that published a few elementary textbooks on the metric system. Compare this rule to 1990.0689.01.
Currently not on view
Object Name
slide rule
date made
Physical Description
paper (overall material)
overall: .3 cm x 20.7 cm x 8.4 cm; 1/8 in x 8 1/8 in x 3 5/16 in
place made
United States: California, Culver City
ID Number
nonaccession number
catalog number
Rule, Calculating
Conversion Chart
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Measuring & Mapping
Slide Rules
Metric System
Data Source
National Museum of American History, Kenneth E. Behring Center


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