● How do I bend aluminum without it fracturing?

[AntoineJackson]

How do I bend the edge over, this time without weakening the bend?

My guess is just heat it; but I have little knowledge of heat-treating/tempering, or even if aluminum even acts like steel in that way. Must I get the aluminum red-hot for it to become "malleable". I know aluminum turns to white powder when heated to much. Assuming there was no fracturing, would the resulting "forged" bend be stronger or weaker?

[aametalmaster]

Some aluminum doesn't like to be bent. So without the grade its hard to tell. How long of bend and how thick?...Bob

[Stefen7]

I will leave the full answer to someone with more experience than me, but here's the basics.


What they will need to know is:
What alloy: different alloys react differently to being heated.
Shape: sheet, flat bar, round or square tubing, etc.
Thickness of stock, or wall thickness and diameter if tubing.
Radius of the bend.
Load or stress placed on finished piece.


Generally speaking, any time aluminum is heated, it loses strength. Some alloys lose more strength than others. Some alloys can be heat-treated to return to their full strength, but it is a very precise process that requires proper equipment and specific instructions. It is not as simple as quenching hot steel.

Steel is very forgiving in being heated and / or bent, aluminum is not. Steel can be heated, hammered, bent and quenched and become stronger. Aluminum will not.

That's the basics, someone else can give you a more complete answer once they know what you are working on.

Good Luck.

[MMW]

I was going to respond but realized that there is no one answer. Previous answers are correct in saying we need more info. My guess is you are trying to bend 6061 sheet & it is cracking.

Many variables but here are some generalizations for sheet. These are just rules of thumb & not set in stone. Just talking general bending.
Bend radius- the smaller radius the more chance of cracking. Radius should never be smaller than thickness of material.
Material grade- 3003 & 5052 will bend. 6061 will not. (this is generalizing as there are ways to bend 6061 but for general bending you use 3003 or 5052)
Grain direction- bend line should go across the grain for the best bend

Having said that a typical sharp 90* bend on a piece of 1/8" aluminum sheet should be a minimum 1/8" inside radius, use either 3003 or 5052 & ideally the bend line should go across the grain. This will give you a nice bend.

If you tell me exactly what you are trying to do I can give you advice.

[Oldgrandad]

I've bent a fair amount of 6061 aluminum, the trick I was taught was to heat it with oxy/act torch. Step 1 use just act. and coat the area to be bent with soot.Step 2 turn on O2 and set rose bud to a normal flame. Step 3 heat part until black soot goes away. You have now annealed your 6061-T whatever into T-0 and it should bend without cracking. The aluminum is now as soft and bendable as it can be. That being said all above statements still hold true about bend radius and such. You will also have to heat treat your part to get it back to its original hardness if needed.

[ryanjones2150]

Oldgrandad...I've done that exact same thing, makes the aluminum like butter. I don't recall the specific alloy I've done it with though, but I generally don't try to make sharp bends in aluminum without annealing it first. I'm also generally not building a work platform out of it so the whatever it is I'm building won't be holding back the 10th Mongolian hoard.

[tarry99]

6061 , 3003 , 5052 & 5086 can all be bent......thinner materials like say .090 down can go 90 degrees with no issue but as thickness increase's so does the need to use a larger bending radius , all 4 types mentioned can also be welded.

[AntoineJackson]

Thanks for all the replies. Its about 6061 thick. tarry99 I think it will bend.

[ryanjones2150]

6061 thick huh? Sounds pretty skookum.

[aametalmaster]

Another spammer that came back later and edited his post. I edited most of it...Bob

[Aeronca41]

Bob-do you know, are these guys typically hoping to pick up some email addresses or hoping to eventually post advertisements or what? This one went to some length before his lack of even basic knowledge gave him away. That was a pretty long initial post he put up.

[ryanjones2150]

How did you figure this guy out? Had some stuff posted up there before I saw it I suppose?

[aametalmaster]

How did you figure this guy out? Had some stuff posted up there before I saw it I suppose?

I just have a hunch and take notes and watch. Then I keep checking. There are a few others still here. I have seen lots over the last 10 years or so...Bob

[Aeronca41]

Thanks for your work!

[ryanjones2150]

Ya man, I appreciate it.