Chrome molybdenum steel. Removes damaged screws without damaging surrounding material. Screws are removed by drilling at low speed on reverse setting. ¼” / 6.35mm hex shank. Overall length 50mm. Chrome molybdenum steel. Removes damaged screws without damaging surrounding material. Screws are removed by drilling at low speed on reverse setting. ¼” / 6.35mm hex shank. Overall length 50mm.