A.0.010mm B.0.015mm C.0.006mm
A.0級 B.1級 C.2級
A.1/4轉(zhuǎn)和1/2轉(zhuǎn) B.1/4轉(zhuǎn)和1/3轉(zhuǎn) C.1/3轉(zhuǎn)和1/2轉(zhuǎn)