Schwarkzkopf, Ernst · New York : J. Wiley & Sons ; London : Chapman and Hall · leaf 158
advisable to use a section of angle iron for temper- ing. The punch projects from the angle, as shown in Fig. 103(A), and the tempering takes place slowly, until a uni- form purple color extends from the shoulder, when the punch is suddenly cooled. Molten lead may frequently be used to advantage in… … 63. Tempering a Reamer. The reamer is heated slowly and evenly to protect the edges from overheating. At a good red heat it is cooled vertically (not horizontally in order that it may not bend) up to the round shoulder and moved slightly up and down and back and forth as explained in section 60, so…
Forging
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