T5 aluminum vs T6 aluminum (Latest Update)

T5 aluminum vs T6 aluminum

T5 aluminum vs T6 aluminum

T is short for Temper, what we talked about the T5 and T6, it is actually the type of heat treatment. 

T5 is the aluminum extruded profile from the extruder with the rapidcooling of the air cooled aluminum (Webster Hardness hardness8–12).

T6 is the aluminum extruded profile from the extruder with the instantaneous cooling water aluminum,the aluminumto achieve higher hardness (Webster Hardness above13.5). 

Today we would like to talk about the solar panel frame material – 6000 series aluminum. Especially 6063 and 6005 aluminum material.

6000 Series is Aluminium-Magnesium-Silicon Alloy. Its representative mark has 6061 Alloy, 6063 Alloy and 6082 Alloy. Different from other 7000 series aluminum alloy, 6000 Series aluminum plate is mainly in T temper, and the most used are T5 and T6. What is the difference between the two T5 and T6?

Difference between T5 aluminum vs T6 aluminum

Before explaining the difference between aluminum solar frame material 6063 T5 and T6 for solar panels, users must first understand the following two noun explanations:

Aging: The process of eliminating internal stress in metals.
Quenching: The metal is heated to a certain temperature and suddenly cooled to meet the required hardness. The strength of 2, 6 and 7 series aluminium sheets can be increased by quenching treatment.

T5 means that the temperature of aluminum solar frame is rapidly lowered by air cooling after extrusion from the extruder to meet the required hardness requirements (wechsler 8-12 hardness). T6 refers to the instantaneous cooling of aluminum solar frame by water cooling after extrusion from the extruder, which makes the aluminium sheet meet higher hardness requirements (wechsler hardness 13.5 or more).

Air-cooled cooling takes a long time, usually 2-3 days, which we call natural aging, while water-cooled cooling takes a short time, which we call artificial aging. The main difference between T5 and T6 states is strength. The strength of T6 state is higher than that of T5 state, and other properties are similar. In terms of price, because of the difference of production process, the price of T6 aluminium sheet is a little higher than that of T5 aluminum solar frame per ton.

difference between T5 and T6 of 6063 aluminum

Mechanical properties difference of T5 aluminum vs T6 aluminum

Below are the mechanical properties of 6063 aluminum alloy, which after T5 and T6 treatment.

Aluminium Alloy         & Temper



Tensile Strength
Yield Strength

Elongation /%



Although the two tempers are different in definition, there is not much difference between the 6063 alloys, but mainly reflected in the difference in mechanical properties. T5 is generally air-cooled and naturally cooled during quenching in aluminum profile plants. T6 is cooled by water to cool the aluminum material instantaneously so that the aluminum profile can reach higher hardness requirements. T6 temper is apparent with more top mechanical properties in strength, elongation, and hardness, and its price is also higher than the cost of T5.

Considering the usage of your final product, if the material requirement on strength and hardness are relatively high, the temper of T6 can be selected, and if no particular need on strength and hardness, the temper T5 can be chosen.

How to keep the machining performance for solar frame material

During the production process, due to the heat and extrusion, the density between the crystals is not uniform, and the energy is not fully released and stored in the inner part, which is called internal stress.

The existence of internal stress will affect the next deep processing, such as bending, stretching, stamping, etc. If the internal stress is not released in advance, it will easily cause the bending of aluminum profiles, wave patterns and surface inequality.

The process of eliminating internal stress is very simple. After the aluminum profiles goes down the assembly line, add a process, use the machine to stretch it, then release the energy inside.

stretch the aluminum profile

Conclusion on T5 aluminum vs T6 aluminum

T5 aluminum can be used for common usage of aluminum profiles and solar frames, But if you have special requirements on aluminum profiles strength, we insist on using T6 aluminum to make it and also have better performance on machining performance.