A.高速鋼 B.高碳鋼 C.合金鋼 D.硬質(zhì)合金
A.碳素工具鋼 B.碳素結(jié)構(gòu)鋼 C.高級(jí)優(yōu)質(zhì)碳素鋼 D.不銹鋼
A.12mm B.13mm C.14mm D.16mm