Durable to keep new shine for a long time.Material M35 Cobalt (HSS-Co)Coated TiAlN coatingHardness HRC62-65Flute 3 flute1/4 inch hexagon handleGroove 3 spiral grooveQuantity 1 piece x step drill bitsize:Model step size4-12 mm 5 4, 6, 8, 10, 12 mm4-12mm 9 4,5,6,7,8,9,10,11,12mm4-22mm 10 4,6,8,10,12,14,16,18,20,22mm5-23mm 10 5,7,9,11,13,15,17,19,21,23mm4-32 mm 15 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32 mmfeature:-Suitable for chamfering aluminum, insulating board, PVC board, steel, aluminum, sheet metal, carbon steel, 304 stainless steel, etc.-3 groove, 3 spiral groove design:Large chip removal, fast heat dissipation, fast drilling, low vibration, high stability and high drilling accuracy.-1/4 inch hexagon handle design, suitable for various types of electric drills-HSS-Co / M35:4241 quenched high speed steel material, the hardness is the same as 6542 material.-Industrial TiAlN electroplating:1. Form Al2O3 protective cover, suitable for high-speed drilling.2. It can work without coolant.3. The hardness is as high as HRC62-65.4. The service life is 2-3 times that of ordinary HSS-Co M35 step drills.Package Included:1 x 3-edge step drill
