Methods of machine shop work : for apprentices and students in technical and trade schools (1914)
Halsey, Frederick A. (Frederick Arthur), 1856-1935 · New York : McGraw-Hill · leaf 47
FiG. 13. Fig. 14. … Fig. 15. Fig. 16. A superior machine shop square. pothenuse and other braces insure that, once made correct, itwill stay so, while the surfaces are large enough to enduremuch use without appreciable wear. The hypothenuse givesangles of thirty and sixty degrees and the short brace has raisedpads…
Machine-shop practice
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
