A.1個(gè)螺距 B.1.5個(gè)螺距 C.2個(gè)螺距
A.Ra4.2μm~Ra2.6μm B.Ra3.2μm~Ra1.6μm C.Ra5.2μm~Ra3.6μm
A.90%~95% B.70%~75% C.80%~85%