Self Piercing, Flow Form, Breakstem and POP rivets-Vehicle body repair, steel and aluminium. SPR Rivets are becoming increasingly popular in vehicle body repair as they enable different materials to be joined together, like steel to aluminium, without causing cathodic corrosion. They also mean repairs can be carried out without welding as the heat produced when joining can change the material's properties.
Self-piercing rivets come in different sizes and lengths. The most common size is 3.3 and 5.3mm. The length is determined by the stack thickness to be joined.