ABSTRACT
Most of the force for producing minimum sealing pressure in a gasket has to come from the bolts. The strength of the bolt must be enough to support the preload, which in turn must be enough to produce the minimum stress that will seal the internal pressure or applied loads. The fatigue strength of a bolted joint must be evaluated from two standpoints: fatigue of the bolt and fatigue of the bolted material. Variable stress in screw or bolt fastenings increases with the flexibility of the connected parts. Shear loads and side sliding are common phenomena for bolted assemblies. Many mechanical devices have been used to prevent unwinding of nuts and bolts. The most common and easiest way to test a bolted assembly is by artificially inducing transverse motion. The use of a gasket in a joint changes the considerations for bolt selection.
