Home / Standards / GB/T 1438.4-1996 GB/T 1438.4-1996 Taper shank twist drills — Part 4: Types and dimensions for extra-long Morse taper shank twist drills 锥柄麻花钻 第四部分:莫氏锥柄超长麻花钻的型式和尺寸 Standard Type GBT ICS N/A CCS N/A Status N/A Issue Date N/A Implementation N/A Responsible Dept N/A Drafting Unit N/A