A.鑄鋼 B.灰鑄鐵 C.非鐵合金 D.高錳鋼
A.0~0.2mm B.0.2~0.4mm C.0.4~0.6mm D.0.6~0.8mm
A.1mm~5mm B.1mm~10mm C.2mm~15mm D.5mm~10mm