7pcs HSS countersink drill bits set with hex wrench
size:3mm,4mm,5mm,6mm,7mm,8mm,10mm.
Material: The drill bit is high-speed steel 4241, and the black part is 45# steel.
On the same axis, after screwing on the screw, the screw cap is below the plane of the board, and the drill ring can be adjusted up and down!
For drilling machines with collets or joints, suitable for drilling in hard wood and wood layers