The blacksmith's guide : valuable instructions on forging, welding, hardening, tempering, casehardening, annealing, coloring, brazing, and general blacksmithing (1907)
Sallows, J. F. (James Francis), 1865- · Brattleboro, Vt. : The Technical Press · leaf 105
THE BLACKSMITH’S GUIDE 92 enough toi harden the teeth, then thrown into the oil. It was allowed to stay there until cooled off, when it was returned to the machine shop and put to work on the pieces mentioned. Treatment of Punches and Dies. — The %6-inch punch and die shown in Fig. 18 have already… … 100,000 holes in I^-inch machine steel. This is 25,000 inches or a little over of a mile of solid metal, and when photographed they were as good as new and looked as if they might punch forever. The only hard part of the die is the bright part around the hole shown in center of picture. The rest of…
Blacksmithing
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
