短语词组短语internal serration 内细齿external serration 外细齿SERRATION BOLT 锯齿状螺丝serration pitch 锯齿节距Serration pattern 锯齿方式Serration Frequency 切屑形成频率serration shaft 锯齿形花键轴;锯齿轴;细齿轴;三角形齿花键轴Serration width 锯齿状的宽度 返回 serration