90° countersinks and deburring countersinks Design: Axial and radial relief ground and CBN deep-ground. Also provided with cutting and clearance angles for the most common materials. Application: Suitable for universal chatter and burr-free drilling, countersinking and deburring work for countersunk screws DIN 963, DIN 964, DIN 965 and DIN 966 in one step. The excellent cutting properties and easy machining process result from the cone-shaped relief grinding on the coat and angle of rake. The countersink achieves the best results with the strongest feed and lowest cutting speed. Note: Sufficient supply of coolant is essential for uncoated designs.