Descriptions: This step drill is made of high speed steel, high hardness and abrasion resistance, durable in use. It automatically deburr holes as you drill, used for thin iron plate, aluminum plate, PV plate, sheet metal opening and reaming. Features: Step drill is made of high speed steel, high hardness and abrasion resistance, durable in use. This HSS step drill is Nitrogen coated to reduce friction and run cooler. Automatically deburr holes as you drill. Convenience to use, no need for a pilot hole. It is used for thin iron plate, aluminum plate, PV plate, sheet metal opening and reaming.(the thickness of the plate <3mm) Specifications: Material: high speed steel HSS4241 Surface treatment: Nitrogen treatment Size: 4-32mm (15 steps: 4, 6, 8, 10, 12, 14, 16, 18, 20, 24, 26, 28, 30, 32mm) Shank diameter: 10mm/0.39inch Shank length: 25mm/0.98inch Blade length: 82 mm/3.23inch Product size:10.7 x 3.2cm/4.21 x 1.26inch Weight:188g Package Induced: 1 x Spiral Grooved Step Drill 1、Step drill is made of high speed steel, high hardness and abrasion resistance, durable in use 2、This HSS step drill is Nitrogen coated to reduce friction and run cooler 3、Automatically deburr holes as you drill 4、Convenience to use, no need for a pilot hole 5、It is used for thin iron plate, aluminum plate, PV plate, sheet metal opening and reaming