Process Encyclopaedia

Joining (generic)

Overview

• It is unusual for a product to be made in one-piece – almost all products consist of components which must be joined in some way.
• The most familiar joining processes are probably mechanical fasteners and adhesives and, as a result, designers often think they understand these the best. However, mechanical fastenings such as snap-fits are often over looked and modern adhesives are greatly under-rated because they are thought of as "just glue".
• In addition to these processes, there are a variety of "hot processes" such as welding and brazing which can often provide stronger and more economic joints for metal parts.
• The one thing which is key for all the processes is to design the joint for the process, and not to design the joint before deciding on the process – a good joint for welding can be disastrous for adhesive bonding, and vice-versa.
• Joints are often a source of weakness in failure – they are very important in design.