7 Pcs 5 Flute HSS Countersink Drill Bit Set Woodworking Screw Chamfering Tool 3-10mm For use in wood and plastic Drill Material:HSS 4241 Chamfering machine Material:45# Steel Chamfer Diameter:15.8mm(0.62") 7 piece sizes sizes 3mm(0.12"),4mm(0.16"),5mm(0.20"),6mm(0.24"),7mm(0.28"),8mm(0.31"),10mm(0.39")