Experts in fastener engineering know bolted joints can be troublesome. But given the lack of attention they frequently receive both during design and assembly, it is surprising they are not more troublesome than they are. I would argue the reason is, historically, many bolted joints have been over designed. However, as industries push for efficiency and lighter weight assemblies, bolted joints are asked to do more with less. Improving fastening efficiency requires increased confidence in the clamp load achieved with a given tightening strategy. Torque control is still the most commonly used tightening strategy, and while advances continue to be made in the accuracy and reliability of tooling, it is still only as good as the consistency in the relationship between torque and tension…READ MORE