Freud CB28057R Industrial Carbide Tipped Cylinder (Hinge) Boring Bits Right Hand 28mm Diameter -10mm Shank - 57.5mm Length 28 mm diameter, 57.5mm overall length, right hand turn, and 10mm shank. 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 Freud's Limited Lifetime Guarantee