Mechanical fastening is a widely used, cost-effective means of joining, which is particularly suitable for thin sheet sections. Fastening encompasses a range of processes that utilise a variety of fasteners including nuts & bolts, screws & rivets, or mechanical interlocks to assemble materials without heating. The high production rate techniques that have been studied at TWI include:
- Clinching - which uses a special punch and die to form a mechanical interlock between the sheet metals being joined
- Self-piercing riveting - in which a semi-tubular rivet is set using a punch and die to flare the rivet within the lower sheet so that no pre-existing hole is required.
Expertise
TWI's expertise in mechanical fastening spans sheet joining, plastics and composites and structural engineering. Industry benefits from a range of specialised support services, consultancy and project work have included:
- advice on process selection
- research into effects of process parameters in clinching and riveting of sheet metals
- hybrid joints - fasteners plus adhesives
- mechanical properties of fastened joints
Resource
- commercial clinching & riveting equipment
- static, fatigue & impact testing equipment
- advice on best practice
- engineering design advice on machine-threaded fasteners
- materials science support
