* Made of chrome-moly steel construction for strength and durability.* To prevent rust and corrosion, the black phosphate finish absorbs and retains oil, repelling moisture.* Has point opening that snugly fits the hex shape of fastener heads, allowing it to apply maximum torque without slipping.* To prevent round-off under stress, it grips the flat sides of fastener heads rather than the corners.* The through-hole in the drive end locks onto the tang of impact wrenches or drivers so it won't fall off or stick on fastener heads.* Widely used in DIY hand-making, household maintenance, and most general repairs.