Conversion Factors, Reference Table for Engineers and Other Executives

This battered table, printed on heavy green paper, gives an alphabetical list of units of measure, conversion factors, and new units of measure. For example, for the unit of measure centimeters, the conversion factor is 0.3937. Multiplying a measurement in centimeters by the conversion factor gives a result in inches.
The table was distributed by Precision Equipment Company of Chicago, Illinois. The back of the table advertises the company’s shelving and safety steps. A sentence at the bottom of the chart reads: Reproduced with the Permission of Foxboro Co. and Exporters’ Digest.
The owner of the table inserted a row with the conversion factor of 1.151 for converting from nautical miles to statute miles.
Exporters’ Digest was published from 1927 through 1958. Foxboro Company was in business from 1912 through 1990. A surviving piece of trade literature suggests that the Precision Equipment Company was in business in the 1950s. Hence the rough date of 1950 assigned to the object.
Currently not on view
Object Name
date made
ca 1950
Physical Description
paper (overall material)
overall: .1 cm x 21 cm x 24.7 cm; 1/32 in x 8 9/32 in x 9 23/32 in
place made
United States: Illinois, Chicago
ID Number
accession number
catalog number
Science & Mathematics
Mathematical Charts and Tables
Measuring & Mapping
See more items in
Medicine and Science: Mathematics
Mathematical Charts and Tables
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John White
Additional Media

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