对微细高速钢麻花钻破坏断口进行了显微观察和测量，根据微小孔钻削实验结果，分析了造成钻头折断的原因和影响其使用寿命的因素。

The fault plane of micro-drill is measured with microscope. According to the result of test, the main elements of destroying drill is investigated.

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这是适用于深孔的通用型高速钢长钻头。

This is general HSS long drills for deep holes.

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这是适用于深孔的通用型高速钢长钻头。

This is general HSS long drills for deep holes.

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