The practical metal-worker's assistant : containing the arts of working all metals and alloys, forging of iron and steel, hardening and tempering, melting and mixing, casting and founding, works in sheet metal, the processes dependent on the ductility of the metals, soldering, and the most improved processes, and tools employed by metal-workers, with the application of the art of electro-metallurgy to manufacturing processes : collected from original sources, and from the works of Holtzapffel, Bergeron, Leupold, Plumier, Napier, and others ... (1851)
Byrne, Oliver · Philadelphia : H.C. Baird · leaf 326
s littledoubt but that, under equal circumstances, ONeills tap would workwith less friction than any other. The principle of chamfering, or relieving the taps, must not, how-ever, be carried to excess, or it will lead to mischief. For example,the tap, if sloped behind the teeth as in Fig. 398,… … irregularly into the metal, and would not produce the smooth, circu-lar, or helical hole, obtained when the tool, Fig. 399, is used. Therelief should be slight, and the surfaces of the teeth then assimilateto the condition of the graver for copper-plates, and thereby directthe tap in a very…
Metal-work · Electrometallurgy · Metallurgy
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