A.4個 B.5個 C.6個 D.7個 E.8個
A.0.2~0.5mm B.0.5~0.7mm C.0.7~1.0mm D.1.0~1.5mm E.1.5~2.0mm
A.1~2mm B.2~3mm C.3~4mm D.4~6mm E.6~8mm