60 Degree HSS Co5 Cross Hole Countersink | BordoCROSS HOLE COUNTERSINKS 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 and rub rather than bite into the material. This clearance is referred