impact hex Hex wrench drill bits. Torsion zone to absorb torque peaks to avoid breakage. For impact driver and heavy screw driving. 10pcs metric hex bits set-1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 5mm, 6mm, 7mm, 8mm. 10pcs SAE hex bits set-5/64inch,3/32inch, 7/64inch, 1/8inch, 9/64inch, 5/32inch, 3/16inch, 7/32inch, 1/4inch, 5/16inch. 1/4inch quick release hex-shank, 4inch long. Extended length to meet more needs. 4 inch long hex bits is longer than the market , more practical and convenient. Extra length provide additional clearance for reaching into tight spaces. After contacting the screw , the collision reaction force generated by the impact screwdriver is absorbed by the torque part, effectively preventing the cutter from breaking. CNC machined tips, S2 alloy steel body, hardened core to increase bit strength and reduce fracture. Manganese Phosphate to prevent rust. Strengthened magnetic impact bit helps you easy pick up screws. Widely used in home repairs, automobiles and other