442377-A is referenced by 2 patents.

442,377. Set - screws. STANDARD PRESSED STEEL CO., Jenkintown, Pennsylvania, U.S.A. Aug. 13, 1934, No. 23320. Convention date, July 16. [Class 89 (i)] To facilitate turning with the fingers, the sides of a set-screw having a tool-receiving socket of less extent than the diameter of the head are knurled or otherwise axially roughened. Reference has been directed by the Comptroller to Specification 125,200, [Class 89 (i)].

Title
Improvements in socket head cap screws
Application Number
GB19340023320 19340813
Publication Number
442377 (A)
Application Date
August 13, 1934
Publication Date
February 7, 1936
Assignee
Standard Pressed Steel Co
IPC
F16B 23/00
F16B 23/00
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