ITEM NAME:Step Drill Bit Set Kit HSS Cone Drill Bit With Coating Description: HSS Titanium Coating - High speed steel along with titanium coating ensures outstanding durability and sharpness, can reduces the friction, runs cooler. Great for steel sheets/ aluminum sheets/ copper/ plastic/ wood board and many other types of sheet metal with ease countersunk. Suitable for Home DIY, and General Building/ Engineering Use. Hex Shank Design - metric, to increase the wear . The two flute design provides a smoother cutting, allows the material particles escape easily for a much more clean drilling operation. Safety and Stability- better clamped on the pistol drill to prevent slippage and shedding during the rotation. 4-20:9steps 4mm,6mm,8mm,10mm,12mm,14mm,16mm,18mm,20mm,3-12:10steps:3mm,4mm,5mm,6mm,7mm,8mm,9mm,10mm,11mm,12mm,4-12:5stepd:4mm,6mm,8mm,10mm,12mm Specification: Material: HSS / High Speed Steel Size: 7cm/2.76inch,7.2cm/2.83inch,7.6cm/2.99inch Package Includes: 3 pieces HSS Step Drill Bit 1 piece canvas bag Note: Color maybe slightly different due to different monitor. The above size is measured by hand, please allow slightly difference. Thanks ! SKU: DMO0019926059028850.HSS Titanium Coating - High speed steel along with titanium coating ensures outstanding durability and sharpness, can reduces the friction, runs cooler. 3 pieces HSS Step Drill Bit. Material: HSS / High Speed Steel.