Very sturdy. Tight concentricity tolerances between drill ⌀ and counterbore ⌀ guarantee exact alignment.
Application:
For through holes for screws to DIN-ISO 273 and countersinking to DIN 74, sheet 2 form H, J and K, medium version. For screws to DIN 912, 6912 and 7984, ISO 1207 (DIN 84).