What grade aluminium for paneling

[TrevS]

Hi all

I am trying to order some sheet aluminium for the rear of my car. The area I will be panelling is very similar to the front wheel arch area and the company I am looking at using offer two types of aluminium 1050A H14 or 5251 H22.

I don't know what grade aluminium I used on the front of the car as it was supplied by Tornado but it's 1.5mm thick so I am planning to get the new aluminium in the same thickness so the panels match.

Could anyone tell me what grade aluminium is best to use though 1050 or 5251? I am planning on cutting the aluminium with a jig saw, fold using my sheet metal folder and then all panels will be powder coated.

Thanks

Trevor

 

[Brett James-McCall]

I have used 5251 as its meant to be better corrosion resistant. You may need thinner to acheive the same effect of a softer grade. I am no materials engineer though. I will tell you that 1.5mm will be way harder to bend in 5251, it tough enough in 1.2 in this cold weather

 

[Phil]

Trevor:
Typically grades containing silicon can be tempered, and some that are available here in the US such as 6061 will age harden or work harden so though they make good panels they can be hard to form, or may crack under close radius bending.
Brett was right on when he mentioned the cool weather, and that being said a little heat applied to the panel right before bending will generally produce a nice crack free bend.
I would and do use the 50 series material for its resistance to corrosion, and bending is not a problem as we regularly bend it at a minimum radius with no cracking, and it also welds nicely.
If you find you are having trouble with bends you may be able to set your brake to bend at a slightly broader radius to eliminate the stresses caused by stretching the outside of the bend into a tight radius, use a little heat and you're all set.
So I guess I agree on using the 5251 material.
Cheers
Phil

 

[Joe H]

Here is a link to aluminum/aluminium alloys. If you click on an alloy it tells you, in most cases, about what the alloy is used for and what shapes are available. This is a very handy site. AircraftmaterialsUK.com Ltd - Source for European and American Aerospace Aluminum Alloys

The alloy that is used in a lot of shaped panel is 3003 H-14 in either .050" or .063" thickness. You can work it and us and English wheel to relieve the stresses when the metal get tight and then put more shape in the panel. It is also easy to anneal.

 

I use NS4 16 gauge.
It's harder but can also be welded.
I believe that's what most use.

 

[TrevS]

Trevor:
Typically grades containing silicon can be tempered, and some that are available here in the US such as 6061 will age harden or work harden so though they make good panels they can be hard to form, or may crack under close radius bending.
Brett was right on when he mentioned the cool weather, and that being said a little heat applied to the panel right before bending will generally produce a nice crack free bend.
I would and do use the 50 series material for its resistance to corrosion, and bending is not a problem as we regularly bend it at a minimum radius with no cracking, and it also welds nicely.
If you find you are having trouble with bends you may be able to set your brake to bend at a slightly broader radius to eliminate the stresses caused by stretching the outside of the bend into a tight radius, use a little heat and you're all set.
So I guess I agree on using the 5251 material.
Cheers
Phil

Thanks for the response Phil. You say you use 50 series for it's corrosion resistance but as I am powder coating my panels would I be better of getting 1050 aluminium? That way I can bend the aluminium easily without any risk of cracks and then coat zinc prime the panels and powder coat them to prevent any corrosion?

Trevor

 

[Malcolm]

Be wary on jig saw cutting your ali sheet. You will get poor quality edges. Treat yourself to a nibbler, shears or guilotine.

 

[TrevS]

Be wary on jig saw cutting your ali sheet. You will get poor quality edges. Treat yourself to a nibbler, shears or guilotine.

I use quite fine blades on my jig saw and find the edges are fine. I've managed to do some really good panelling on the front using a jigsaw so cutting isn't the issue it's just making sure the aluminium I get can be bent fairly easily in my folder without cracking but will also be corrosion resistance.

Here is an old picture of some of my front panels before powder coating

Trev

 

[Phil]

Trev:
If you are powder coating then I guess the more workable material is the answer.
I shear all my panels when possible, but if you are cutting with a saw one trick we use is to cut outside your lines a bit and clamp a piece of angle to the material at the line, use a flap or finishing wheel to grind to the line, then all you will need is a slight de-burr and the cuts will be super straight. A file generally will take the burrs off nicely.
Cheers
Phil

 

[TrevS]

I use NS4 16 gauge.
It's harder but can also be welded.
I believe that's what most use.

Keith, can you tell me is NS4 5251?

Trev

 

[Brett James-McCall]

.Yes.

 

[zollis]

One aspect I would like to point out is that the " H " value of an alloy determines it's hardness. For the same grade eg. 5251 H xxx will be harder to form than when it is in "O" condition. 5251- "O" is dead soft .








Z.C.

 

[TrevS]

One aspect I would like to point out is that the " H " value of an alloy determines it's hardness. For the same grade eg. 5251 H xxx will be harder to form than when it is in "O" condition. 5251- "O" is dead soft .

Z.C.

The aluminium I am looking at is 5251 H22 in 1.5mm thickness.

The Tornado build manual says to use 18 gauge aluminium for paneling which would be just over 1mm in thickness but the stuff Tornado sent with the chassis and that I've been using is exactly 1.5mm according to my micrometer. So in order to keep the panels the same on the car I need to use 1.5mm aluminum but I want to check that 5251 H22 isn't going to be impossible to bend.

I might have to order a couple of samples of 1050 and 5251 to see what matches the aluminium I've been using

Trev

 

[Mick Ridley]

Trevor,

Have a look around this site.

There is lots of really usefull info on aluminium. Look at the Machanical Properties, That will basically tell you how stiff/strong the alluminium is.
Proof Stress, and Yeild Strength, are basically the same. its just a different way of measuring it

This is a link to the machanical properties of NS4 5251 H22

Technical Information - Aluminium Alloy - Commercial Alloy - 5251 - H22

The yeild strength (proof stress) of NS4 is 165 MPA. That is the point where the material stays bent, ( ie, it yeilds ). Im useing 6082 T6, on my chassis that has a yeild of 310 MPA. So in comparison the NS4 is very soft

Technical Information - Aluminium Alloy - Commercial Alloy - 6082 - T6~T651

Im bending mine on an Edwards 36" finger folder, quite easily

If you have a sheet metal folder you will have no problem folding NS4 H22

Here is a list of comercial alluminium, and its Machanical Properties

Technical Information - Aluminium Alloy - Commercial Alloy datasheets

This is a link to its sister company. Amari Aerospace that specialise, in aerospace alloys

Amari Aerospace Ltd - Products - Aluminium Alloy

Im sure you will find this info usefull and intresting

mick
Trev if you worried about bending the NS4, email me your address, and ill send a sample up to you. so you can see if you can bend it ok

 

[Brett James-McCall]

Trev,
I use 1.2mm 5251 and at times it can be a little bugger. 1.5mm will just be harder

 

[TrevS]

Well I took the plunge and decided to try the 5251 H22 aluminium and it arrived this morning. At 1.5mm the thickness matches my current aluminium perfectly but it's definitly stiffer and I am a little worried I'll be able to bend it without it snapping and be able to achieve the sharp folds I like.

I'll have a go at forming one of the new panels over the next few days and report back. Worse case scenario is I'll have to keep this stuff as spare for things like making a battery box etc and order the 1050 aluminium

 

[Brett James-McCall]

If you are worried, run a little heat over it prior to bending

 

[TrevS]

Hey guys, good news. Just finished putting a couple of folds in my first panel using my new aluminium and it came out fine, phew. It's stiffer than my older panels but generally not much more difficult to bend and I am happy with the results

Thanks for all your help chaps

 

[Brett James-McCall]

Trev,
I assume you've checked the trailing arm location and the amount of movement

 

[TrevS]

Trev,
I assume you've checked the trailing arm location and the amount of movement

Yes sir, I did check the movement and tried to make to opening big enough to allow for movement. I won't be fitting these panels until later in the build so once the car is off the build table and on wheels it should be easier to check the amount of travel

Trev