This Steel Countersink Drill Set is use on steel, aluminum & other metals, plastic or wood. Enlarge or countersink holes, deburr edges. Great drill accessory for any work shop backed by manufacturer's lifetime warranty Features: Four piece set includes bits for drilling pilot holes for screw sizes 3mm, 4mm, 5mm, 6mm. Special designed steel counter sleeve countersinks or counter bores pilot hole. Adjustable counter sleeve depth with wrench. Drill and countersink for wood screws without changing bits. Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. Chamfer is 5 flutes, in the process of using, can discharge the wood more rapid, sink hole disposable drilled smooth, screw cap perfect embedded in the surface of workpiece. Drill Head: HSS 4241 with Titanium coating. Heat treated & tempered high-carbon steel with titanium coating for superior cutting power. Specifications: Material: HSS Drill 4241 Black chamfer drill body material: steel #45 Diameter of Chamfer: 15.8mm Size: 3mm x 60mm(L)/ 4mm x 75mm(L)/ 5mm x 85mm(L)/ 6mm x 93mm(L) Shank: 1/4 hex shank Package size: 14*10*2cm/5.51*3.93*0.78in Package weight: 115g Note: Item color may show sight aberration due to different shooting light and monitor display. Package included: 4pc* Woodworking Chamfer 1pc* Hex Shank