手工攻制螺纹时（特别是小直径的螺纹） ,常有扭断丝锥的现象。丝锥被扭断的位置 ,大多在丝锥的工作部分。由于残留的丝锥处于工件表面之下 ,因此极难取出。既使能够取出 ,螺纹的质量也会受到一定的影响。有些重要的工件 ,常常会因此而报废 ,十分可惜。为了解决这个问题 ,我们 When manually tapping thread (especially small diameter thread), often torn tap phenomenon. Taps are twisted position, mostly in the working part of the tap. Since the remaining tap is below the workpiece surface, it is extremely difficult to remove. Even if can be removed, the quality of the thread will also be affected to some extent. It is a shame that some important work items are often scrapped. In order to solve this problem, we