This seven piece countersink drill bits set includes bits for drilling holes for screw sizes 3mm, 4mm, 5mm, 6mm,7mm,8mm,10mm. Special designed steel counter sleeve countersinks or counter bores hole. Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. In the process of using, it can discharge the wood more rapid, sink hole disposable drilled smooth, screw perfect embedded in the surface of workpiece. Features - ColorSilver - Package Size: Approx. 8 - Material: Steel. - -bit design: cutting CNC grinding teeth, tricuspid centering is better, will not produce offset, quasi-drilling and fast. - Easy to use: drilling length can be adjusted simply by loosening and tightening the set. - Round handle design: suitable for the market bench drill, the use of more convenient. - Removable Adjustable: use a wrench to remove or adjust woodworking and five- chamfering. - removal: large chip flute and five-edge chamfering machine, the operation of faster discharge of sawdust, you will get a nice smooth surface on any type of hard, wood or aluminum. Package list: 1 x 7Pcs Three-Pointed High-Speed Steel Drill Bits Set Woodworking Countersink Drill Woodworking Chamfer (3-10mm)