12 PIECE & 12 SIZES: 1.5, 2, 2.5, 3.2, 3.5, 4, 4.5, 4.8, 5, 5.5, 6, 6.5mm. Twist Drill Bit Set made of High Speed Steel, high hardness, good wear resistance and durability. This HSS Drill Bits surface Titanium coated, which increase the hardness of the drill bit and reduces heat buildup, make the twist drill bit more wear-resisting for longer life. Suitable for drilling holes in alloy steel, wood, nonferrous metal, cast iron and hard plastics. Compared with the ordinary drill, with a quick change hexagonal handle, handle diameter 6.35mm (1/4 "), fixture is more stable, more convenient to replace. For electric screwdriver can be mounted 1/4 hexagonal handle electrical tools..
