Starrett FCH0278 Fast Cut Bi-Metal Holesaw 73mmStarrett Fast Cut Bi Metal Holesaws provide a smoother, faster cut on a wide range of materials, when compared to the previous constant pitch saw. Improved tooth material and 5. 5 TPI 25mm tooth form for enhanced heat and wear resistance and greater product life. Specifically suited to cutting stainless and mild steel sheet, they will also cut through tubes with a wall thickness of up to 3mm (1 8in). Cutting Depth: 41mm. Starrett FCH0278 Fast Cut Bi