The structural Bolts following EN 14399-4 and DIN 6914 is to use thinner nuts and shorter thread lengths to obtain the required ductility by plastic deformation of the threads within the nut. The structural bolt assembly is used in both preloaded and non-preloaded applications and it can be argued that in the event of failure by thread plastic deformation the assembly still acts as a non-preloaded assembly. These assemblies are more sensitive to over-tightening during preloading and therefore require more site control. If severely over tightened during preloading the mode of failure by plastic deformation of the engaged thread of the bolt assembly offers little indication of impending failure.
Structural bolts ...
The structural Bolts following EN 14399-4 and DIN 6914 is to use thinner nuts and shorter thread lengths to obtain the required ductility by plastic deformation of the threads within the nut. The structural bolt assembly is used in both preloaded and non-preloaded applications and it can be argued that in the event of failure by thread plastic deformation the assembly still acts as a non-preloaded assembly. These assemblies are more sensitive to over-tightening during preloading and therefore require more site control. If severely over tightened during preloading the mode of failure by plastic deformation of the engaged thread of the bolt assembly offers little indication of impending failure.
Structural bolts grades are 8.8 and 10.9, and these characteristics are large under head surface, reduced setting, enables preloading, smaller noticing, less surface pressure, rfl mark available
