它基本上由在淬硬钢衬套下将零件夹持到位的夹持装置组成，钻孔作业中钻头穿过这些衬套，通过它们来导向。

Basically it consists of a clamping device to hold the part in position under hardened-steel bushings through which the drill passes during the drilling operation. The drill is guided by the bushings.

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回火作业包括将淬硬钢重新加热到低于临界范围的某一温度然后以任意速率冷却。

The operation consists of reheating quench-hardened steel to some temperature below the critical range followed by any rate of cooling.

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