XR Black is a structural screw for internal or external use available in a range of sizes that is made from hardened steel, designed for fast entry and fixing. The screw has a hex washer head and is black in colour hence the name and the coating is C4 rated guaranteeing a minimum 15 years in timber and which has been salt spray tested beyond 2000 hours. Socket bits are sold separately and work ideally with impact drivers and drill drivers.