1. 紧捻：hard surfacing 敷焊硬合金表面;表面硬化 | hard twist 紧捻 | hard twisted waste 硬回丝
2. 硬拈,硬捻：hard tube pulser ==> 电子管脉冲发生器 | hard twist ==> 硬拈,硬捻 | hard twisted waste ==> 硬回丝