There are lots of exceptional aluminiums to suit a huge array of different requirements. For example, you can choose pure 1000 series grades for their great corrosion resistance. Or you can opt for alloys like those in the 5000 and 6000 series for higher strength. The choice is even broader when you start looking at tempers. At Brindley Metals we offer a wide selection of these materials, including 5754 (H111) aluminium sheet and coil.
What is tempering?
Before you choose an aluminium, it is a good idea to ensure you are clear on what tempering is and how it affects the metal. It is basically processing to alter the mechanical properties of the material. Typically it will focus on vital things like the ductility and strength. It can also release internal stresses.
There are two broad groups of aluminium alloys if you look at the tempers. The first is non-heat treatable alloys. Here there hasn’t been any kind of major heat treatment. Instead the processing is via cold working. This can involve things like rolling and extruding. Working the metals like this encourages work hardening, changing the properties. As a result, these alloys are often known as work hardened. Tempers here are always H designation.
The second group is alloys that have had heat treatment. This involves heating plus cooling and then ageing. The latter can be natural or artificial. With natural, the metal ages at room temperature for a longer period to gain its full strength. Artificial ageing holds the metal at a higher temperature so it gains full strength in a shorter period of time. The tempers here have the T designation.
Designations
With non-heat treatable alloys there are eight broad designations. The first four range from H1X to H4X. This refers to the processes that have been done to temper the metal. H1X has only had work hardening. H2X has had it plus partial annealing. H3X has had the hardening as well as low temperature treatment to stabilise it. H4X has been work hardened and stoved.
The other four designations here are HX2, HX4, HX6, and HX8. These refer to the level of hardening. For starters, HX2 means quarter hard. Then you have half hard (HX4), three quarters (HX6), and fully hardened (HX8).
Some notable designations here include H14. This is the general term for work hardening and can indicate processing has been done to improve strength but reduce ductility. It is also known as strain hardening.
If you see the designation H24 it indicates partial annealing. This process is almost the opposite of H14 because it increases the ductility but reduces the strength. Some refer to it as temper let-down.
Finally, you may see H34. This is the designation for stabilising. Some non-heat treatable aluminium alloys can gradually age-soften at room temperature. The stabilisation is necessary to improve ductility and relieve internal stress.
Temper codes specifically for aluminium plates
You can also find a full range of different temper codes specifically for plate. Again there are eight. When you look at our 5754 (H111) aluminium sheet and coil you will see the designation right away. The H111 here indicates there has been some work hardening due to the shaping processes. However, there is not enough to achieve the H11 temper.
The other codes include:
- H112 – alloys with tempering because of the shaping but no controls over hardening or thermal treatment.
- H115 – armour plating
- H116 – alloys with a temper to improve corrosion resistance
- H321 – alloys that have been strain hardened but not enough to achieve a H32 temper
- H323 – a slightly different version of H32 to give more resistance to stress corrosion cracking
- H34 – as we said above this indicates stabilisation
- H343 – a slightly different version of H34 with more resistance to stress corrosion cracking
Ordering 5754 (H111) aluminium sheet and coil
We hope the information here helps to provide more details of what some of the designations mean for different aluminiums. However, if you are still unsure of what to choose, you can ask us. We are always happy to offer advice and to recommend a metal for almost any kind of use.