Professional Quality: The bi-metal hole saw is made of premium quality M42 high speed steel, sturdy and abrasion resistant. High speed steel teeth are heat treated, high hardness (65HRC), reusable and durable. Chip removal designPre-drilled holes have a favorable impact on chip evacuation to improve the speed when removing cylindrical iron chips in the hole. Easy to use Thanks to its design with clean edges, this hole saw cuts easily and effortlesy. The spring around the bit automatically pushes the washer out of the saw, immediately after completing the hole. Can be used with an adapterstandard in all drills with SDS-plus or hexagonal chuck. Wide Uses: The hole saw is often used in wood, plastic, aluminum, non-ferrous metals, copper, plasterboard and other materials. Suitable for bank drill, electromagnetic drill, gun drill,hammer drill, etc. Convenient for you. ",