俄交“机床与工具”1962年6期“丝锥结构的一些改进”一文有两点颇值得参考:1.缩短校准部丝罐一般丝锥都有一个比较长的校准部,用作引导、校准和作为刃磨的储备部分,但据本文介绍,把校准部螺纹磨到仅剩下两、三牙,其生产率(以加工螺纹的件数表示)为普通丝锥的7.4倍,切削扭矩此普通丝锥的亦要低 Russian exchange “machine tools and tools ” 1962 six “Some improvements in the structure of the tap ” a text has quite two points worthy of reference: 1. Shorten the calibration department Silk cans generally tap has a longer calibration department, Guide, calibration and as a sharpening reserve, but according to this article, the calibration department thread mill until only two or three teeth, its productivity (as the number of threads) is 7.4 times the ordinary tap, cutting torque Ordinary tap should be low