Tightening torque measurement
The tightening torque of bolts is measured with a specific torque wrench. This control method is applied in all cases in which the persistence of an initial applied torque must be verified over time (e.g. the tightening torque of the bolts imposed by the project or by the manufacturer), specifically in elements for which a loss of performance coincides with a vulnerability increase to external actions, such as in the case of load-bearing metal structures (steel bridges, lattice towers, …) or motorway non-structural manufacts (guardrails, sound-absorbing barriers, PMVs, …).
Reference technical regulation: UNI EN 14831:2005