Precision ground, hardened high carbon steel. Fine pitch spiral pulls auger into workpiece and single spur slices the timber ahead of cutting edge, producing accurate holes. Fits all SDS Plus Drills. Sizes: 10, 13, 19, 22 and 25mm. Precision ground, hardened high carbon steel. Fine pitch spiral pulls auger into workpiece and single spur slices the timber ahead of cutting edge, producing accurate holes. Fits all SDS Plus Drills. Sizes: 10, 13, 19, 22 and 25mm.