TCT multi-tooth heavy duty cemented carbide alloy with high hardness, rust-proof, sturdy and durable; With a spring to prevent blocking during operation Category Bore Diameter 22mm/0.86, 30mm/1.18, 35mm/1.38, 45mm/1.77, 50mm/1.97, 65mm/2.56 Should be installed in an electric drill for use. Widely used for stainless steel plate up to 3mm thick and iron plate less than 10mm thick, also for hole processing in aluminum alloy. Perfect for installing locks, knobs in doors and cabinets, or drilling larger diameter holes through desks, etc. 6pcs high quality carbide 22-65(mm) which can cut holes in steel, stainless steel, copper, brass, fiberglass, Formica, iron, aluminum, wood and various kinds of pipes in seconds Features: 1. 100% brand new and high quality. 2. Made of high quality alloy steel, the blade is extremely sharp and cut-resistant. Good perforation. 3. By using our HSS hole saw set, it can be used for perforating thick steel plates and thick-walled metal pipes. 4. When cutting