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Aluminium grades?? School me please

Posted: Tue Mar 27, 2012 7:53 pm
by YEA 13B
Ive been doin some research and pricing for new links. In another thread on here at the moment brooksey has recomended 7075 grade, i got a price for that and i was told i can only buy it in 63mm diameter and it was $635 for 3.56m?? Can i use 6061?? has anyone used 6061??

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 5:38 am
by CanberraMav
There is some info in another thread if your search by evanstaniland. He lists where he got his and i got mine from there about 2 months ago. I paid about $360 i think from memory for 4 x 1.2 metres of 7075 T6. They were up in Qld somewhere.

The 7075 is more expensive but a better option for links than other grades. There is info on the net if you search 7075 vs ......

Sorry dont have time to pull it all up for you at the moment but i did a heap of research before i got mine. I got the aluminium sent straight from the supplier to Chris at Dragtec customs and he supplied me the heims and drilled and tapped for me.

There are big price differences from shop to shop.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 7:40 am
by KiwiBacon
It depends entirely on the application. 7075 is high strength but cannot be welded without losing all it's strength. It is only suitable for mechanically fixed parts (bolts, clamps, press-fits etc).
6061 is the default industrial spec, when treated to T6 schedule after welding it has very good strength.
7005 is a 7000 series grade which can be welded without heat treatment while maintaining most of it's strength. But it does need to age following welding.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:01 am
by evanstaniland
7075 can be bought from shape aluminum in qld, they can cut and post.
I have bought 1.5", 1.75", and 2" solid round from them, I get it tapped and fit heims.
If you get stuck let me know and I'll get there number!
Cheers

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:04 am
by TheBigBoy
But solid is weaker than hollow?

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:05 am
by evanstaniland
Never had a drama, saw hollow ones at In the states snap

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:28 am
by KiwiBacon
TheBigBoy wrote:But solid is weaker than hollow?
Surely you are taking the piss.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:42 am
by TheBigBoy
KiwiBacon wrote:
TheBigBoy wrote:But solid is weaker than hollow?
Surely you are taking the piss.
No im not. Hollow section cold rolled dome is stronger than solid. Not sure how that relates to ali though.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:58 am
by KiwiBacon
TheBigBoy wrote:
KiwiBacon wrote:
TheBigBoy wrote:But solid is weaker than hollow?
Surely you are taking the piss.
No im not. Hollow section cold rolled dome is stronger than solid. Not sure how that relates to ali though.
In your example you aren't comparing the same material in two different forms (hollow and solid), you are comparing two completely different material treatments.

For the same material, solid is stronger than hollow. Always.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 9:04 am
by TheBigBoy
How do you come to that? Look it up. Hollow take much more stress to bend it.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 9:13 am
by TheBigBoy
Ive just had a search about ali. They are saying that solid is stronger than hollow. But the intergrity of the extra inside mass doesnt do a whole lot. So hollow sections isnt that far behind it for a lot less weight. Which kinda contradicts the tests Ive seen on tv shows. They put solid and hollow in between 2 blocks on the ground and slowly drove a car onto it. The solid bent before the hollow did. Im sure someone on here can clear it up.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 9:14 am
by KiwiBacon
TheBigBoy wrote:How do you come to that? Look it up. Hollow take much more stress to bend it.
Bollocks.
Go ask any engineer to put you straight. This one has better things to do.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 9:17 am
by TheBigBoy
KiwiBacon wrote:
TheBigBoy wrote:How do you come to that? Look it up. Hollow take much more stress to bend it.
Bollocks.
Go ask any engineer to put you straight. This one has better things to do.
Run sheep run... Sorry couldnt resist.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 10:20 am
by evanstaniland
As far as I was aware alloy won't bend as such it will flex but return....until it snaps anyway!

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 1:42 pm
by 4X4 shorty
YEA 13B wrote:Ive been doin some research and pricing for new links. In another thread on here at the moment brooksey has recomended 7075 grade, i got a price for that and i was told i can only buy it in 63mm diameter and it was $635 for 3.56m?? Can i use 6061?? has anyone used 6061??

wow thats dear.

As people say 7075 is the one to use, a rep who comes vist my work from ullrich aluminum said 7075 is not made in oz and is all imported hans dearer then 6206 or 6061 whatever. I have 6206 or 6061 ( basically the same i think ) 50mm in my truck and don't see an issue with it and a know of a few cars running it for a few years and havn't had an issue I got in 4 lenghts of it when we built 2 cars last year and I dont think it cost much more then that price of one above

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 3:01 pm
by evanstaniland
7075 is stronger than 6061, I'm not sure where shape in qld get it from but when I spoke to ulrich in newcastle they had no idea what I was talking about, that being said shape told me that they are a supplier for ulrich, but shape sell direct to the public off the top of my head a length if 2" solid 7075 was $249

Evan

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 5:35 pm
by 4X4 shorty
thats not a bad price evan 7075 is aircraft grade and 6061 in structural grade so I have been told if you would believe a sales rep :) ??

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 5:44 pm
by KiwiBacon
4X4 shorty wrote:thats not a bad price evan 7075 is aircraft grade and 6061 in structural grade so I have been told if you would believe a sales rep :) ??
Either can be aircraft grade.
"Aircraft Grade" means the material can be traced right back to the smelter. It is all about traceability and means absolutely nothing in terms of material strength or properties.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 5:50 pm
by 4X4 shorty
yeah I don't clame to be an expert but Ive got 6061 for my links and havn't had a darma fingers crossed

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 6:58 pm
by moose2367
I have been told that hollow is stronger too, if i recall correctly it was because of the greater surface area, don't know for a fact just what i remember being told once

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 8:20 pm
by evanstaniland
moose2367 wrote:I have been told that hollow is stronger too, if i recall correctly it was because of the greater surface area, don't know for a fact just what i remember being told once
Think you need to read up, hollow and solid has been touched on.

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 9:18 pm
by YEA 13B
Yea i rang shape today, 3.66m of 50mm 7056 was as evan said $248ish plus freight to act, which surprisingly they couldnt tell me how much that would be??

But as james has said he has used 6061 without any dramas yet. Which goes back to my original thoughts, Can i use 6061 without to much drama? It would be alot cheaper plus i can buy it locally

Re: Aluminium grades?? School me please

Posted: Wed Mar 28, 2012 9:23 pm
by 4X4 shorty
YEA 13B wrote:Yea i rang shape today, 3.66m of 50mm 7056 was as evan said $248ish plus freight to act, which surprisingly they couldnt tell me how much that would be??

But as james has said he has used 6061 without any dramas yet. Which goes back to my original thoughts, Can i use 6061 without to much drama? It would be alot cheaper plus i can buy it locally

haha just use it and tell everyone its 7075 :lol:

Re: Aluminium grades?? School me please

Posted: Thu Mar 29, 2012 12:08 pm
by metak
From what I have been told solid will be stronger then hollow however hollow will not flex as much but if you were to bend the two solid will except more angle and return to its orginal shape where hollow will not fully return atleast this is what I have been told

Re: Aluminium grades?? School me please

Posted: Thu Mar 29, 2012 2:39 pm
by Wendle
6061 is ok, not as good as 7075, but ok.

I've run 6061 links and molested them hard and they hold up. If you drive big rocks you will bend them eventually, but still way, way better than a mild steel link of comparable size.
You can straighten them out, it takes about 20t to press a 46dia link back straight, so it's pretty stout stuff.

6061 also gouges up pretty badly compared to 7075, every rock hit leaves a little razor edged groove. Be careful touching them :lol:

Re: Aluminium grades?? School me please

Posted: Sat Mar 31, 2012 12:42 pm
by KiwiBacon
metak wrote:From what I have been told solid will be stronger then hollow however hollow will not flex as much but if you were to bend the two solid will except more angle and return to its orginal shape where hollow will not fully return atleast this is what I have been told
If your solid and hollow bars are the same diameter, then flexing them the same amount results in the same surface stress. The surface gets the most stress in bending.
But if you apply the same bending load, the hollow will flex further and experience higher stress.

How far a material will flex before taking a permanent set is it's yield strength. Higher yield strength means it can be flexed further and still return to it's original shape. Exactly how much depends on the shape, the material and the load. Calculating stress, deflection and material choice is what a large number of engineers are hired to do.

Re: Aluminium grades?? School me please

Posted: Mon Apr 02, 2012 9:24 am
by danaz
I think what people are thinking of with hollow bar is strength to weight ratio. A hollow bar will have a higher strength to weight ratio than the same size / material solid bar. The solid bar will still be stronger.

Re: Aluminium grades?? School me please

Posted: Thu Apr 12, 2012 5:52 pm
by Baja Burley
What's the weight and strength (yield) difference between 7075, mild steel and say 4130 chromoly? All in a solid 50mm?? Just curious. Are more people going aly because of weight?

Re: Aluminium grades?? School me please

Posted: Fri Apr 13, 2012 8:20 am
by KiwiBacon
Baja Burley wrote:What's the weight and strength (yield) difference between 7075, mild steel and say 4130 chromoly? All in a solid 50mm?? Just curious. Are more people going aly because of weight?
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