perfect for making countersunk countersunk holes and countersunk holes for plugs.The countersinks are carbon steel, the surface is titanium coated, sturdy and durable, not easy to rust, long service life.This kit is suitable for DIY at home and daily , it allows to drill easily and effectively, without burr.Universal size with all types of drill, drilling machines, including vertical drilling machine, and another common milling cutter.Used in hardness 25 under the part, such as carbon steel, metal, insulation boards, PVC board, woodFor the 90 chamfer piece hole or conical hole, the chamfer edge edges and angles of the treatment angleCan be completed finished the treatment of the cone for one time. Applicable to the small cutting process.Neat edges, smooth, no broken edge, small resistance to chamfering, high in the hole, more durableFlute with big chip, fast for the elimination of Three blades of medium for laborious, each force of the blade smaller, high efficiency and more durableSpecifications:Handle: round handleColor: Gold + SilverMaterial: High speed steelSurface treatment: titanium coatedCUT:Diameter of the head * Diameter of the stem * Length6.3MM: 6.3MM * 5MM * 37MM8.3MM: 8.3MM * 6MM * 40MM10.4mm: 10.4mm * 39MM * 6MM12.4mm: 12.4mm * 10MM * 46MM16.5mm: 16.5mm * 47mm * 10MM20.5mm: 20.5mm * 47mm * 10MMPackage Contents:8Pcs * Three Chamfering DrillingOnly the above package content, other products are not included.Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.