Disston Blu-Mol sheet-metal Holesaw – 38mm Thin-walled BI-Metal Holesaw is manufactured from M42 steel and features an 8tpi constant pitch for a smoother cut and reduced vibration. Integral ¼” quick change hex shank, which is ideal for cordless drills. The pilot drill features a built-in spring for automatic plug removal, which also prevents over cutting. Ideal for cutting mild steel, brass, aluminium, stainless steel and plastic.