These industrial carbide tipped cylinder (hinge) boring bits are designed for accurate boring and the two wing cutters and two spur cutters prevent bottom side tear out. The 57.5mm long bits have a 10mm x 20mm shank with an adjustable top screw making them compatible with most boring machines. Drills all composition materials, solid surface materials, plywoods, hardwoods, and softwoods. Use on automatic and manual muti-spindle boring machines. 35 mm diameter 57.5mm overall length right hand turn 10mm shank.