Various heat treatments can be applied to hardened components. This is carried out generally to aid subsequent machining and enhance component stability.
Suffixes to the material grade are used to denote the heat treatment carried out: UK and equivalent USA and EN suffixes are shown below:
| Treatments | UK | USA | EN |
| As cast / maufactured | M | F | F |
| Solution heat treated and stabilised | TB7 | T4 | T4 |
| Artificially age hardened | TE | T5 | 5 |
| Solution heat treated and artificially age hardened | TF | T6 | T6 |
