A.200-230 B.205-235 C.210-240 D.215-245
A.0.1~1mm B.0.2~lmm C.0.3~1mm D.0.4~1mm
A.0.2~0.5 B.0.5 C.0.2~0.8 D.0.8
A.2~2.5 B.2.5~3 C.3~3.5 D.1.5~2
A.4 B.5 C.6 D.7