This standard is applicable to the replaceable guide post for countersinking drills with tapered shank and 90° tapered face countersinking with replaceable guide post. This guide post can also be used for other types of tools.
GB/T 4266-1984 history
2004GB/T 4266-2004 Detachable pilots for use with counterbores and countersinks
1984GB/T 4266-1984 Detachable pilots for use with counterbores and countersinks