Hexagon head bolts are intended for mounting steel or wooden components together with nuts and washers, or directly in threaded holes together with washers.

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.