H119 Bi-Metal Holesaw Impact Sutton Tools Impact Bi-Metal Holesaw are designed for use in impact drivers. Suited to cut sheet metal up to 3mm maximum thickness. Ideal for electrical installation, junction boxes, ducting and general sheet fabrication. 1/4" Hex shank suitable for impact drivers Ejector spring quickly ejects waste material Thin wall 8 TPI for fast and burr free cutting Stop shoulder to prevent over drilling Bi-Metal HSS premium quality for toughness and longer life