Version:
Countersinks radially relief ground. Chip flutes are ground from solid up to size 31. Chip angle varies with the countersink ⌀ for optimum chip formation. Countersink point and circumference are relief ground and cut easily.
Economy countersink version.
Note:
For countersink bits with shank 6.3 mm (1/4 inch) see Group 67.
For suitable reducing adapters for tools with MT shanks see
No. 343000-343530.