Hexagon head bolts are intended for mounting steel or wooden components together with nuts and washers, or directly in threaded holes together with washers. The bolt has an undersize thread (6az) before hot-dip galvanization and is only compatible with nuts that have normal thread tolerance (6H).

In order for a bolted joint to work correctly and be able to counter static and varying loads for long periods the bolts must be preloaded, for example, by tightening with a given torque. Preloading must normally be held to such a level that the combined load in the bolt does not exceed the bolt material’s tensile yield limit. For the correct installation of hexagon head bolt grade 8.8 to be correct a flat washer of at least HV200 hardness should be used.