Hold tight

Fasteners are the engineering world's equivalent of drummers in a band. They are not glamorous, but many everyday products would simply fall apart without them.

There are many ways of fastening components together, perhaps the most familiar being that used on cars, where mechanical methods hold just about all the non-welded parts in place. Audi's A4 and A5 models, for example, feature a bonnet latch fastened to the bodywork by Profil's RSN and RND rivet nuts.

These are fully encapsulated in 30 per cent glass-reinforced Polyamide 6 to form an integral part of each vehicle's impact crumple zone as part of the installation process, and are designed to provide high-strength fastening. The manufacturers claim they are suitable for use with up to 1,200MPa high-strength steels.

The latches are considered to be a 'safety critical' part of the structure, and require high-integrity fastening, as the prospect of the bonnet opening at high speed on a motorway is not an option.