5 Pce 10-30mm 90 Degree HSS Co5 Cross Hole Countersink Set Without exposed diamond the blade

Without exposed diamond the blade will not cut

Bordo Metric 19 Piece Quick Silver M2-HSS Twist Drill Set in ABS Plastic Case

Saber HSS Countersink Triple Flute 90 Deg

Re-cut your hole using a new size hole saw

5 Pce 10-30mm 90 Degree HSS Co5 Cross Hole Countersink Set Without exposed diamond the blade5 Pce 10 30mm 90 Degree HSS Co5 Cross Hole Countersink Set Cross hole countersinks are ideal for countersinking and deburring in a wide range of materials including ferrous and non ferrous metals. The intersection of the hole and cone form the cutting edge on the tool. The cone is not truly symmetrical as it is essential that the cone retreats away from the cutting edge as the tool rotates. If this does not occur the cutting edge will lack clearance