Assembly methods and joining techniques

Assembly methods and joining techniques

Assembly Methods

Mechanical fasteners

  • Screws offer high adjustable strength, ease of assembly and disassembly. Different types of heads (slot, Phillips, hex) and thread pitches offer various levels of tightness.
  • Bolts and nuts are used in thick materials and applications requiring high strength and durability; nuts can be loosened for adjustments.
  • Rivets permanently join steel and aluminium parts; cannot be easily undone, hence, provide a secure and tamper-proof join.

Adhesive bonding

  • Epoxies, Cyanoacrylates, and Polyurethanes are examples of adhesives that provide strong bonds and fill gaps; choice depends on materials being joined and performance requirements (flexibility, temperature resistance, setting time).

Press fits

  • Joining parts by force fit or interference fit where one part is slightly larger than the other. The larger part is pressed into the smaller one, and friction holds them together.

Welding

  • Resistance welding, Arc welding, Gas welding, and Laser welding are techniques where parts are coalesced by heating at the joints either with or without a filler material.

Joining Techniques

Adhesive bonding for polymers

  • For plastics, proper surface preparation (cleaning, roughening) is essential to ensure effective adhesive bonding.

Soldering and Brazing for metals

  • For non-ferrous metals and alloys, Soldering (using filler material with a melting point less than 450°C) or Brazing (filler material with a melting point above 450°C) are often used.

Welding for Polymers and Composites

  • Hot gas welding and ultrasonic welding used for thermoplastics.
  • Adhesive bonding and mechanical fastening (rivets, screws) used for composites.

Turning process for woods

  • Various lathe operations like turning, facing, grooving, parting off, etc., can be used to create intricate joinery in wood turning projects.

Remember to consider the nature of the materials being joined and the intended application when choosing an assembly method or joining technique. Factors such as the strength required, the need (or not) for disassembly, and the conditions the join will be exposed to (chemical, thermal, mechanical stresses) will all impact the best method to use.