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 276
Fig. 268.—Gear hobbing machine set for spur gears. … Fig. 269.—Gear hobbing machine set for helical gears. 266 METHODS OF MACHINE SHOP WORK interference with one another which, from the illustration, mightbe inferred to take place.
Machine-shop practice
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
