Execution: Very good chip removal and ideal chip flow due to spiral grooves. Easy to re-sharpen. The countersink is secured against twisting in the holder. Note: Flange countersinks are also available in HSS with optional TIN coating, as well as with soldered carbide cutting edges and with ISO turning inserts type "T" upon request. Use: For countersinking screws according to DIN or through the appropriate combination of countersink and pin for creating stepped holes or countersinks outside of the standard.