In the production of aluminium alloy components, costs of rectification of distortion after heat treatment can become inordinately high, especially if those components are either large or of complex shape. With small parts of simple shape, the problem is avoided by forming in the solution-treated condition so that no further heat treatment is required, the principal limitation being that the forming must be completed within about two hours of heat treatment, otherwise the subsequent age-hardening process will be too far advanced. For more complex shapes, forming in the annealed condition is much easier, and indeed may be the only practicable procedure if a rubber press is to be used. Obviously pressing the components is generally quicker and more economical than manual forming. The problem that arises after forming—manual or press—in the annealed condition is that the components must then be solution treated, during which a water quenching operation can cause distortion, calling for the rectification previously mentioned.