on the tap短语¹⁸⁰⁰⁹⁸⁺¹ 基本例句 🌏在乞讨东西 The primary problem in tapping of small deep holes in difficult-to- cut materials is that the friction and wear on the tap flank are very heavy due to the spring back of the machined surface. 难加工材料小深孔攻丝的根本问题是已加工表面回弹引起后刀面摩擦、磨损严重。 chemyq