目前我国工具厂所供应的标准丝锥,最大名义直径为52毫米,而实际上随着我国机械制造业的迅速发展,在汽轮机,锅炉及其他重型机械制造厂,经常会遇到加工大于52毫米的螺孔。兹根据自己在工作中见到的有关资料及我厂现在使用的M120×6丝锥的结构特点,作简要介绍,供有关设计人员参考 At present, the standard taps supplied by the tool factories in our country have a maximum nominal diameter of 52 mm. In fact, with the rapid development of China’s machinery manufacturing industry, steam turbines, boilers and other heavy machinery factories often encounter machining of more than 52 mm Screw hole. Hereby according to their own work to see the relevant information and I plant now used M120 × 6 taps structural features for a brief introduction for reference to the designer