Large hexagon bolts for 10.9 high-strength steel structures are mainly used for fastening steel structures. High-strength large hexagon bolts have larger hexagonal heads than ordinary hexagonal heads and have thicker heads than ordinary ones. In addition, the large hexagon head high-strength bolts are first used with impact type electric wrenches or torque adjustable electric wrenches, and the final type must be torque type electric wrenches; the usual configuration is composed of a bolt, a nut, and two washers. Mainly used in the construction of bridges, railways, large venues, high-rise buildings, stations and airports, hydropower stations, large playgrounds, etc. The main specifications include: M16, M20, M22, M24, M27, M30, etc. The main length range is: 40mm-220mm. Product standard: GB / T 1228-2006 Surface treatment: zinc plating, phosphating, blackening, dacromet, etc.