4-20mm Ti HSS Spiral Groove Step Drill Bit with Hex Shank Material:High speed steel(HSS) Step quantity:9steps; Total length:7cm Color: Golden(as picture shown) Step diameter: 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm,18mm,20mm Package Included: 1pc HSS hex spiral grooved step drill