[Hex Shank Diameter] These 1/4 “hex shank nut drivers come with 14 piece drill bits. Rod diameter: 6.35 mm. Shank length: 2.2 cm. REMARKS: Magnetic Free! [High hardness and quality] The nut driver drill bit is made of industrial grade chrome vanadium steel, with high hardness after being forged and tempered at high temperature. The surface has been sandblasted against corrosion and rust for long life. [Various Sizes] The Hex Driver Set contains various sizes to meet your needs. Power Nut Screwdriver Bits (SAE): 3/16, 1/4, 9/32, 5/16, 11/32, 3/8, 7/16 inch; Power Nut Screwdriver Bits (Metric): 5mm, 5.5mm, 6mm, 7mm, 8mm, 10mm, 12mm. [Wide application] Hexagonal screwdriver socket fits any drill or chuck, such as power cord drills, pneumatic screwdriver, socket wrench, electric screwdriver, pneumatic drill, electric drill, manual screwdriver, screw gun. Widely used in auto parts, woodworking, home DIY, machine repair and maintenance. [Easy to store and transport] The driver bit set comes