Slide Chart, Quick Slide Thread Elements

This paper model slide chart has an envelope held together by staples and a rectangular slide, It contains tables relating to the size and shape of screw threads, as standardized in the mid-20th century United States. Tables on one side are for the “National Fine Series,” those on the other side for the “National Coarse Series.” Fine screws move a relatively short distance each time the screw is turned, and have greater locking power.
Assuming that screws are of the general form proposed by William Sellers of Philadelphia in 1864, the chart gives the depth of the thread element, the width of the flat portion of the base, the tap drill size to be used in fabricating the screw, and the best wire size for measuring the screw (that is to say, the wire size that will just touch the thread at the pitch diameter). It also indicates the maximum and minimum dimensional tolerances for different classes of fit from the loosest (class 1) to the most precise (class 4).
A mark on the front reads: QUICK SLIDE (/) THREAD ELEMENTS. A mark on the back reads: COPYRIGHT 1946 BY CAPELL DESIGNING CO. BOX 993 CHURCH ST. STA. NEW YORK 8, N.Y. The back is stamped: [copyright symbol]CI I pub. 430. Below this is the date stamp: FEB - 7 1946. A nearby stamp reads: SURPLUS (/) DUPLICATE and shows the seal of the Library of Congress.
Rockford D. Robbins and John E. Capell of New York copyrighted the instrument in February of 1946. It seems likely that this was the copy of their device submitted to the Copyright Office of the Library of Congress. No manufactured example of the instrument is yet known.
Bruce Sinclair, “At the Turn of a Screw: William Sellers, the Franklin Institute, and a Standard American Thread,”
Technology and Culture , vol. 10, No. 1 (Jan., 1969), pp. 20-34
United States Library of Congress, Catalog of Copyright Entries 1946 Works of Art . . .
Currently not on view
date made
Capell Designing Company
place made
United States: New York, New York
Physical Description
metal (overall material)
paper (overall material)
overall: .2 cm x 25.5 cm x 10.3 cm; 3/32 in x 10 1/32 in x 4 1/16 in
ID Number
catalog number
nonaccession number
Credit Line
Transfer from Smithsonian Institution Libraries
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Mathematical Charts and Tables
Data Source
National Museum of American History, Kenneth E. Behring Center


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