1. Metal joining techniques
Methods for assembling/disassembling products made from metal

2. Learning objectives
To be aware of the need to join metal parts in a permanent or temporary fashion
To be familiar with a range of permanent and temporary joining techniques.
To be able to select an appropriate joining technique for a particular design situation

3. The requirement for joining, assembly and disassembly
Metal products are often comprised of sub-assemblies joined together.
It is not cost effective to produce metal products ‘carved’ from a single piece.
Products made from metal are generally exposed to high wear and fatigue. Parts will wear and need to be replaced.

4. Permanent joining The product has no requirement to be disassembled
Welding using combustible gas or electrical current
Soldering using a secondary low-melting point metal
Rivetting
Adhesives/sealants

5. Welding
Oxygen-Acetylene
MIG-Metal with Inert Gas
Arc/’Stick’ welding

6. Soldering Soft soldering PCB/Plumbing Silver soldering (ring) Brazing
(bike)

7. Riveting
Set rivets
Spitfire
fuselage
Pop rivets
Land rover
body

8. Adhesives for metal Epoxy resin (Araldite, two-part thermoset)
Polyurethane adhesive/sealant
Lotus Elise
Body tub

9. Non-permanent The product may need to be dismantled.
Screw thread fastenings (sometimes called self-tapping screws)
Machine thread fastenings
(bolts and nuts)
Pins and clips
(often for retaining wheels)

10. Design considerations
Does the product need to resist flexing?
Will the product be under extreme load?
Will vibration be an issue?
Will the product incorporate wearing parts that will require replacement?
Will the product be very large/heavy and need to be transported?
Will the product be made from differing materials?

11. Click-view film
‘Joining Metals’
Make notes on the worksheet