Superb QualityOur countersink bits are made of premium steel and extra hard carbon steel and coated with titanium, and the cutting edge is hardened and sharpened for better sharpness. Durable and won't rust easily6 different sizesContains sizes 6.3mm, 8.3mm, 10.4mm, 12.4mm, 16.5mm, 20.5mm; the handle diameter, These universal sizes are compatible with various types of drilling machines, including vertical drilling machine, and/or common milling cutterOutstanding performance With quick change, drilling three blades with groove, 90 angle on the tip for accurate and proper milling, suitable for working metal and some non-metal materialsSharper and strongerThe whole set of drill bits uses high frequency quenching for heat treatment, high density grinding, with titanium to prevent rust. High strength, good toughness. This kit is perfect for DIY in office, workshop, home, easy to drill without stress or burrVarious UsesThese drill bits are widely used for openings in wood, boring, chamfering etc. Also applies to MDF, plywood, acrylic, PVC board and soft metal such as aluminum, copper etc.Features:Durable and practical.Ideal for wooden boards, fiberboard, particleboard, plywood, plastic, aluminum edged.Suitable for various uses DIY, home and building/engineering.For 90 chamfer piece hole or tapered hole, chamfer edges and anglesCan be completed to complete the treatment of the cone. Applicable to small cutting process.Edge clean, smooth, no broken edge, low resistance to chamfering, high precision to drill, more durable Specifications:Material: HSSSurface Treatment: Titanium CoatingCUT:Diameter head diameter * Rod diameter * Length6.3mm * 5mm * 37mm8.3mm * 6mm * 40mm10.4mm * 6mm * 39mm12.4mm*8mm*46mm16.5mm*10mm*47mm20.5mm*10mm*47mmParckage includes:1x 6pcs three chamfer drills