Metal, High Speed Steel Brand: SALI Product Dimensions: 8 length x 3.5 width cm Color: Blue Style: Industrial Item Weight: 0.11 kilograms High-Quality Material & Wear-Resistant Construction: The cutting edge of the bimetal hole saw is made by fusing high-quality cobalt-containing M42 high-speed steel (hardness HRC67-69) with ultra-fine grain refining technology, maintaining "professional-grade" cutting precision. The center drill uses high-quality 4341 steel, vacuum hardened + deep cooling treatment, 1800MPa core bending strength, and 200% increase in toughness compared to ordinary 4241 steel. 200% Durability UP & Efficient Work: Bimetal composite processing, wear resistance 200% UP, the lifespan of one is 3 times that of conventional hole saws. It is easy to handle high-strength continuous work scenarios, cutting efficiency is 40% up, while keeping the cut smooth and burr-free, saving time and effort. Abundant Sizes & Easy Combination: Our bimetal hole saws come in a wide range of sizes, from 15mm to 200mm. Packing contents: M42 bimetal hole saw *1. Depending on the size, it can be used for various material thicknesses and different size hole requirements. Easy to combine, easy to clean and adjust, the hole saw maintains optimal operating condition for a long time. Wide Range of Applications: The hole cutter is applicable to wood, plastic, resin, plywood, gypsum board, aluminum, thin stainless steel, and thin iron. It supports various applications such as ventilation ducts, ventilation fans, wall lights, ceilings, tables, display shelves, washbasins, distribution boards, corrugated iron, piping, and electrical work. The high-strength, corrosion-resistant 4341 steel triangular shaft can be used with electric drills and drill presses. Because this product is a non-hexagonal shaft, a suitable drill chuck is required separately when using an impact drill. Note: Hold the hole saw perpendicular to the material and start cutting at low speed. Never tilt the hole saw during processing. When cutting metal, apply cutting oil or water while working. Wear protective gear such as goggles and a mask.