hss4241 high speed steel stepped drill bit: 10–45 step twist drill bit cutting flute, nitrogen coated Made from high speed steel and nitrogen coated to reduce friction and run cooler Spiral Flute Cut; automatically deburr holes as you drill it Application: suitable for below 25 hardness of the work piece, such as carbon steel, sheet metal, insulation board, PVC board, planks, wood and thickness less than 5mm 8 steps in increments: 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm Specifications ?: Color ?: Black (as picture shown) Material: high speed steel 4241 Surface ?: nitrogen treatment (increasing hardness and abrasion resistance) Rod: triangle round handle Type: 10–45 mm (10,15,20,25,30,35,40,45 mm) Total size ?: 45 x 100 mm Weight ?: 350 g Included in delivery ?: 1 x10–45 step drill bit