Dalsteel Metals Pty Limited

Data Sheets

Aluminium Alloy // General Information // Temper Designations

Aluminium Alloys are supplied in a very wide range of tempers with two principal groups:

Non-heat treatable alloys - Alloys whose strength/mechanical properties are achieved by cold working (rolling, extruding, etc.). Sometimes called work hardening alloys, Temper is denoted by letter H.

Heat treatable alloys - Alloys whose strength/ mechanical properties are achieved by heat treatment followed by cooling and natural or artificial ageing. Temper denoted by letter T.

Heat-Treatable Alloys

Solution heat treating - The process of heating aluminium at prescribed temperature for a prescribed time and then cooling rapidly usually by quenching in water.


Natural ageing (T1, T2, T3, T4) - The process which occurs spontaneously at ordinary temperature until the metal reaches a stable condition.  This hardens the metal after solution heat treatment.


Artificial ageing (T5, T6, T9) - The process of heating for a prescribed period (2-30 hours) at a prescribed low temperature (100-200ºC) until the metal reaches a stable condition.  This hardens/increases strength after solution heat treating quicker than natural ageing and to a greater level.

Non Heat-Treatable Alloys

Work hardening (H14) - General term for processes which increase strength of aluminium and reduce the ductility, (e.g. rolling, drawing, pressing, stamping). Sometimes called strain-hardening. 


Partial annealing (H24) - A heating process which reduces strength and increases ductility of aluminium after work hardening.  Sometimes called temper let-down.


Stabilising (H34) - A low temperature thermal treatment or heat introduced during manufacture which stabilises the mechanical properties.  This process usually improves ductility and is only applied to those alloys which, unless stabilised, gradually age-soften at room temperature, (i.e. non-heat treatable range.)  The purpose of stabilising is to relieve the residual internal stress in the metal. Mainly used for 5000 series alloys.

This Data is indicative only and as such is not to be relied upon in place of the full specification. In particular, mechanical property requirements vary widely with temper, product and product dimensions. All information is based on our present knowledge and is given in good faith. No liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon.

Please note that the 'Datasheet Update' date shown above is no guarantee of accuracy or whether the datasheet is up to date.

The information provided in this datasheet has been drawn from various recognised sources, including EN Standards, recognised industry references (printed & online) and manufacturers’ data. No guarantee is given that the information is from the latest issue of those sources or about the accuracy of those sources.

Material supplied by the Company may vary significantly from this data, but will conform to all relevant and applicable standards.

As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose, whether expressed or implied.

Advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. All transactions are subject to the Company’s current Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.

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