A common question we get is what temper is best for bending aluminium?
Intro:
Aluminium is prized across industries for its strength-to-weight ratio, corrosion resistance, and versatility. However, when it comes to bending, not all aluminium alloys behave the same—especially when considering different temper conditions such as T0, T4, T5, and T6. At Inductaflex, where precision and innovation in aluminium profile bending are core to our service, understanding these temper states is crucial to ensuring optimal results and long-term structural integrity.
Understanding Aluminium Tempers in Bending Applications
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T0 (Annealed):
T0 is the softest temper of aluminium, having undergone full annealing to relieve internal stresses. It is the easiest to bend, offering minimal spring-back and high ductility. This makes it ideal for complex or tight-radius bending where minimal cracking risk is required. However, it lacks the strength needed for many structural applications unless subsequently heat-treated. -
T4 (Solution Heat-Treated and Naturally Aged):
T4 offers a balance between formability and strength. It bends well, with a lower risk of cracking than harder tempers. However, it’s typically not the end-state for structural applications. Many projects require it to be artificially aged to T6 after bending to restore full mechanical properties. -
T5 (Cooled from an Elevated Temperature and Artificially Aged):
T5 is partially hardened and offers improved strength while maintaining moderate formability. It can be bent, but care must be taken due to the increased risk of cracking, especially in tight radii or thin-walled profiles. -
T6 (Solution Heat-Treated and Artificially Aged):
T6 is the hardest commonly available temper. It offers excellent mechanical properties but comes with the highest risk during bending. Cracking, stress fractures, and surface deformation are common risks when attempting to bend T6 directly.
Why Bending T6 Aluminium to tight diameters can be risky
Attempting to cold-bend T6 profiles to tighter radii can lead to:
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Surface cracking or crazing, particularly along the extruded grain lines.
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Internal microfractures that may not be immediately visible but compromise structural integrity.
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Spring-back issues, which make precise bending difficult.
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Tooling damage, as high forces are required, potentially affecting softer nylon dies.
Even with assisted bending technologies like those used at Inductaflex, bending T6 is carefully considered.
Cost Implications of Bending T4 then Artificially Ageing to T6
While T4 offers a safer path to complex bends, the post-bending artificial aging process introduces:
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Additional processing steps include holding the material at 160–180°C for several hours in an industrial oven.
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Energy costs are associated with maintaining consistent thermal cycles.
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Handling and logistical complexity, as profiles must be carefully managed to avoid warping or contamination.
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Lead time extensions, as ageing can take up to 8 hours or more, depending on profile size and material specification.
Despite these costs, this method often delivers the best outcome when precision bends are required without compromising on final strength—a critical concern in aerospace, transportation, and architectural applications.
Conclusion: Selecting the Right Temper for the Right Job
At Inductaflex, our expertise in aluminium bending ensures that each project is approached with a tailored solution. Whether it’s bending soft T0 for tight radii, managing the transition from T4 to T6, or carefully heating T6 for safe forming, we bring deep technical knowledge and cutting-edge machinery to every challenge.
Choosing the correct temper and bending method is not just about feasibility—it’s about performance, safety, and longevity.
Talk to our team today to discuss your next aluminium bending project.
We have put together a quick reference table to give a good idea of the bending capabilities of a number of alloys and tempers. Note that we have not included all possibilities, and if your product is not listed, that does not necessarily mean we are unable to bend it.
Quick Reference Table
Our aluminium bending machine range have been service tested over years to prove their abilities. Bending a wide range for profiles in all shapes, sizes, alloys and tempers. We’ve found that time, effort and expertise allows our machines to complete projects that would have otherwise been impossible on other machinery.
