Standard No.:	GB/T 4256-2004
English Name:	Core drills with parallel shanks and with Morse taper shanks
Chinese Name:	直柄和莫氏锥柄扩孔钻
Chinese Classification:	J14
Professional Classification:	GB    National Standard
ICS Classification:	25.100.30 25.100.30    Drills, countersinks, reamers 25.100.30
Issued by:	AQSIQ; SAC
Issued on:	2004-2-10
Implemented on:	2004-8-1
Status:	superseded
Superseded by:	GB/T 4256-2022 Core drills with parallel shanks and with Morse taper shanks
Superseded on:	2023-2-1
Superseding:	GB/T 1141-1984 锥柄扩孔钻
Language:	English
File Format:	PDF
Word Count:	1500 words
Price(USD):	115.00
Delivery:	via email in 1~3 business day

本标准规定了直柄扩孔钻和莫氏锥柄扩孔钻的型式和尺寸及其公差等。本标准对上述每种型式的扩孔钻都列出两个表：——优先采用的尺寸；——以直径范围分段的尺寸。
本标准只推荐米制尺寸，对这种扩孔钻今后也只推荐米制尺寸。除另有说明外，这种扩孔钻均制成右切削。