Sterling Metric Converter Slide Rule

This ten-inch, one-sided plastic rule has a yellow base, a white slide, and a transparent indicator. Identical logarithmic scales are on the top and the bottom of the base. Both sides of the slide are marked with pairs of metric and conventional units. On one side, the user can read off conversions between: inches and centimeters; meters and feet; meters and yards; miles and kilometers; square inches and square centimeters; square meters and square feet (times ten); square meters and square yards; and square miles and square kilometers. The other side of the slide permits readings of cubic inches and cubic centimeters (times ten); cubic meters and cubic feet (times ten); cubic meters and cubic yards; liters and quarts; ounces and grams (times ten); kilograms and pounds; metric tons and short tons; and gallons and liters.
The top left of the base is marked with the letters SP in a circle and the word STERLING. The top middle of the base is marked: METRIC CONVERTER. The bottom left of the base is marked: MADE IN U.S.A. The rule was received with its original packaging, a clear plastic cover on a blue paper backing. The packaging is marked at the top: SP STERLING #651 (/) metric (/) converter. At the bottom, it is marked: BORDEN ® (/) © 1972 STERLING PLASTICS (/) DIVISION OF BORDEN CHEMICAL, BORDEN INC. (/) MOUNTAINSIDE, N.J. 07092 (/) MADE IN U.S.A.
Sterling Plastics, a 20th-century manufacturer of drawing instruments for schools, was purchased by Borden Chemical in 1970. Since Sterling stopped making slide rules in 1972, this example of model number 651 was probably one of the last rules produced by the company. The five braces holding together the base of the instrument are also consistent with this date; early Sterling slide rules had only two braces. For instructions, see 1990.0689.03. For a Sterling slide rule with standard scales, see 1988.0807.01.
Reference: Mike Konshak, "Sterling Plastics,"
Currently not on view
Object Name
slide rule
date made
Sterling Plastics
Physical Description
plastic (overall material)
paper (case material)
overall: 1 cm x 34.5 cm x 9 cm; 13/32 in x 13 19/32 in x 3 17/32 in
place made
United States: New Jersey, Mountainside
ID Number
accession number
catalog number
Science & Mathematics
Slide Rules
Rule, Calculating
Measuring & Mapping
Conversion Chart
Metric System
See more items in
Medicine and Science: Mathematics
Slide Rules
Metric System
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of George A. Norton III
Additional Media

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