Aluminium alloys are ubiquitous in transport applications because they provide engineering materials with good strength-to-weight ratios at reasonable cost. Further applications make use of the corrosion resistance and conductivity (both thermal and electrical) of some alloys. Although normally low strength, some of the more complex alloys can have mechanical properties equivalent to steels. Owing to the many benefits of aluminium alloys offered to industry, there is a need to identify best practices for joining them.