American Machinists' Handbook was a McGraw-Hill reference book similar to Industrial Press's Machinery's Handbook. (The latter title, still in print and regularly revised, is the one that machinists today are usually referring to when they speak imprecisely of "the machinist's handbook" or "the machinists' handbook".)
The somewhat generic sound of the title American Machinists' Handbook, and the ambiguity of its apostrophe usage, no doubt contributed to the confounding of the two books' titles and identities. It capitalized on readers' familiarity with American Machinist, McGraw-Hill's popular trade journal. But the usage could have benefited from some branding discipline, because the confusion over whether the title was properly "American Machinist's Handbook" or "American Machinists' Handbook" or "American Machinist 's Handbook" was (and is) considerable. ("American Machinist 's Handbook" would be parallel to the construction of the title "Machinery's Handbook"; perhaps McGraw-Hill's handbook's title was originally conceived as that and later was muddied into "American Machinists' Handbook".)
Although McGraw-Hill's American Machinists' Handbook appeared first (1908), it is doubtful that Industrial Press's Machinery's Handbook (1914) was a mere me-too conceived afterwards in response. The eager market for such a reference work had probably been obvious for at least a decade before either work was compiled, and presumably the appearance of the McGraw-Hill title merely prodded Industrial Press to finally get moving on a handbook of its own.
American Machinists' Handbook, coedited by Fred H. Colvin and Frank A. Stanley, went through eight editions between 1908 and 1945. In 1955, McGraw-Hill published The new American machinist's handbook. Based upon earlier editions of American machinists' handbook (sic; note the apostrophe usage difference within that title), but presumably the book did not compete well enough with Machinery's Handbook, because no subsequent editions were produced. Meanwhile, Machinery's Handbook has continued to be regularly revised and updated, right up to today, and it is still a "bible of the metalworking industries."
Renewal data from Rutgers. All works after 1923 with renewed copyright are presumably still protected.