A.1~2mm B.2~3mm C.3~4mm D.2~4mm
A.0~1mm B.0~2mm C.0~3mm D.0~4mm
A.允許的咬邊深度為0.5mm B.允許的咬邊深度為1mm C.允許的咬邊深度為1.5mm D.不允許咬邊