A.(0.1~0.2)D B.(0.2~0.3)D C.(0.5~0.7)D D.(0.8~0.9)D
A.切削速度 B.鉆頭剛度 C.鉆頭頂角落 D.進給量
A.0.3~0.4倍 B.0.5~0.7倍 C.0.8~0.9倍 D.1~1.2倍