Stock code: 601677
Stock code: 601677
A cracked bend usually points to the wrong temper, not a weak machine. Aluminum sheet hardness for bending is one of the first choices to get right, because it decides how much the material can stretch before the outer edge tears. It can also show up later as small edge cracks that are easy to miss at first. Choosing the temper before bending is far easier than fixing a rejected batch afterward.
> The harder the sheet, the higher the strength—and the less room the material has to stretch during bending.
O, H14, and H24 look close on paper, but they behave differently at the press brake. Here is how to match them to real bending work.
|
Temper |
Bending behavior |
Good for |
Watch out for |
|
O |
Easiest to bend, rarely cracks |
Dead-sharp bends, complex forming |
Too soft, finished part can deform |
|
H14 |
Needs a larger bend radius |
Exposed parts, scratch resistance |
Edge cracking when radius is tight |
|
H24 |
More forgiving at the bend |
90° bends, strength plus formability |
Harder than O, so springback needs compensation |
This table is not absolute, because alloy, thickness, and tooling all change the result. It does help you rule out clearly unsuitable tempers. The basic logic is simple: softer bends more easily, harder needs more room.
H14 is work-hardened by cold rolling, so it carries more internal stress and has lower elongation. H24 receives an additional partial anneal, which releases some of that stress and improves elongation. Think of H24 as keeping its strength while becoming easier to work with. During bending, the outer fibers stretch. The more elongation the sheet has, the less likely those fibers are to tear.
In practice:
– If you need both strength and bendability, look at H24 first.
– If you need a harder surface for scratch resistance, consider H14 but allow a larger bend radius.
– For a near-zero inside radius or a dead-sharp bend, start with O temper.
1. Inside radius close to zero, dead-sharp bend
Start with O temper. It is the most reliable choice for this kind of bend.
2. Small inside radius, but not a dead-sharp bend
Start with H24. Do not jump straight to H14, because the edge-cracking risk is higher.
3. Moderate inside radius
H24 is the balanced choice. It gives you useful strength without making the bend too difficult.
4. Generous inside radius with a scratch-resistant surface
H14 can work, but increase the bend radius and pay attention to bend direction.
If you are unsure, protect the bend first and worry about hardness second. A bend that cannot pass inspection makes higher hardness meaningless.
– Bend line direction: Keep the bend line perpendicular to the rolling direction whenever possible. Bending along the rolling texture makes cracking more likely. Rotating the bend line by 90 degrees in the layout can often solve the problem.
– Sheet thickness: Thicker sheet is harder to bend in the same temper. Under the same radius, the outer fibers stretch more, so you may need a softer temper or a larger radius.
– Springback control: O temper springs back unpredictably, while H tempers are more consistent. H tempers make die compensation easier to plan.
Read the inside bend radius first. If it is very tight, go to O. If it is moderate, H24 is usually the safer starting point. If it is generous and the exposed surface must resist scratching, H14 can work. If you are still unsure, try H24 first.
A test bend with the actual thickness and radius is more reliable than theory. If the edge still looks poor after trial bending, step down one temper or open the bend radius slightly.
One point on scope: we focus on aluminum sheet and coil rolling and temper control. We do not provide surface treatment or post-bending processing.
– Harder is always better?
No. Higher hardness usually means lower elongation, so the bend zone is more likely to develop micro-cracks.
– O temper solves everything?
It bends easily, but the finished part can be too soft and may need support or reinforcement.
– H14 and H24 are basically the same?
Their strength is close, but H24 is usually more stable and forgiving in bending.
– Hardness alone tells the whole story?
No. Elongation matters more at the bend. Two tempers with similar hardness can behave very differently.
Q: For a 90-degree bend, should I choose H14 or H24?
A: H24 is usually the safer starting point because it offers better elongation and lower edge-cracking risk.
Q: Can O temper handle a dead-sharp bend?
A: Yes, O temper is the softest and the most reliable choice for a near-zero inside radius.
Q: Can H14 be bent?
A: Yes, but it needs a larger bend radius and the bend line should run perpendicular to the rolling direction.
Q: Does a harder temper always make a better finished part?
A: No, higher hardness usually means lower elongation, so the bend zone is more likely to develop micro-cracks.
Q: What if I am not sure which temper to choose?
A: A test bend with the actual thickness and radius is more reliable than guessing from a data sheet.
Q: Do you supply O, H14, and H24?
A: Yes, we supply aluminum sheet and coil in O, H14, H24, and other tempers for bending applications.
Temper Supply and Support
Mingtai Aluminum supplies aluminum sheet and coil in O, H14, H24, and other tempers, with stable temper performance for bending work. Share your thickness and bend radius, and we can help confirm a suitable temper; aluminum sheet hardness for bending is much easier to lock down with those two details.
