手工攻螺纹时,丝锥折断在工件中是常有的事,而取出断丝锥往往很困难。分析丝锥折断的原因,除了工件材质、丝锥变钝、基孔过小或铁屑未清除等因素外,大多是由于丝锥对基孔歪斜太多所造成。这就相当于不断增大着单边的切削用量,直至丝锥所受的扭力超过了极限强度而断掉。多年来解决的方法是:将旧丝锥在砂轮机上改磨其头部,使直径略小于 Taps manually, the tap broken in the workpiece is common, and remove the tap is often difficult. Analysis of the causes of broken taps, in addition to the workpiece material, blunt tap, the base hole is too small or iron is not clear and other factors, mostly due to the tap on the base hole askew caused by too much. This is equivalent to increasing the amount of unilateral cutting, until the tap suffered torque exceeds the ultimate strength and broken. Over the years to solve the method is: the old tap on the grinder modified its head, the diameter slightly smaller than