| 摘要 |
A drill-chuck jaw is made by first forming an elongated metal body with a toothed back face and a front face, then machining a longitudinally extending groove having sides and a floor in the front face, and forming inwardly projecting and longitudinally spaced retaining bumps on the groove sides. A hard-metal insert is fitted into the groove between the retaining bumps and then bonded to the body in the groove. the body is heat-treated, that is annealed, before machining the groove in it to reduce internal stresses. Then the body is cleaned and oiled to prepare it for machining and to eliminate any oxidation created by the heat treatment. After machining the body and before fitting the insert the body is deburred and cleaned again. Normally the insert is bonded to the body by soldering or brazing In order to allow the insert to seat directly on the jaw and not be held off it by the solder a channel is formed between the insert and the body in the groove. The insert is bonded to the body by filling the channel with the solder. The channel can be formed in the insert or in the body. |
