Giaone HSS Drill Twist Bits Set for Aluminum Iron Copper Brass Metal 14-25.5mm

For general using drilling in wood, aluminum, malleable iron, plastic etc. Higher wear resistance, toughness and bending resistance. Increase the groove, chip more smoothly, drilling fast. for Sharp for head, through a special grinding edge, to speed up the punching speed. Full grinding process, the surface is more smooth, more smooth groove, processed products less burr.