Starrett STRHS25AX FCH0100 Fast Cut Bi-Metal Holesaw 25mm The Starrett Fast Cut Bi-Metal Holesaws combine a new tooth material and a 5.5 TPI/25mm tooth form with increased resistance to heat and wear. Providing a smoother faster cut on a wide range of materials when compared to the previous constant pitch saw. 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 FCH0100 Fast Cut Bi Metal Holesaw has the following specification: Diameter: 25mm (1in).