Subland twist drills with cylindrical shanks for holes prior to tapping screw threads 攻丝前钻孔用圆柱柄阶梯麻花钻
2.
Subland twist drills with morse taper shanks for holes prior to tapping screw threads 攻丝前钻孔用莫氏锥柄阶梯麻花钻
3.
Subland twist drills for holes prior to tapping screw threads . part 1 : the types and dimensions for subland twist drills with parallel shanks 攻丝前钻孔用阶梯麻花钻第1部分:直柄阶梯麻花钻的型式和尺寸
4.
Subland twist drills for holes prior to tapping screw threads . part 1 : the types and dimensions for subland twist drills with morse shanks 攻丝前钻孔用阶梯麻花钻第2部分:莫式锥柄阶梯麻花钻的型式和尺寸
