Outer Limits 4x4 Board

I think the main problem with building with SHS is not the actual strength of the tube, but the clearance the profile needs at the mount.. With a circular section, you can have a nice radius cut into the top/bottom gussets/plates/whatever, to clear the link when the angles start getting big. With a square section, you have to open that radius out square, loosing a lot of strength, bringing up all the stress risers, etc..
Seamless tube is also cheap, and readily available up to about 10mm wall...

You could also consider the 50 x 25 x 3 RHS if width at the mount is an issue.

DirtPigs wrote:You could also consider the 50 x 25 x 3 RHS if width at the mount is an issue.

the 50mm high would maybe give you the same problem, look at your standard rear lower arm mount on the axle, and you'll see what I mean. Would the link only being 25mm wide take alot of strength out of the weld to thebushing tube at the end?? The twisting torque wouldn't be spread out across as large an area??

Any idea what the yield stress of the seamless tube your using is Carlton?

Do you know of any links on the internet that give sizes available? Every time I try and search for tube I don't get anything useful.

Scott wrote:Any idea what the yield stress of the seamless tube your using is Carlton?

No, I don't.. I was originally going to use the same stuff sam uses in the overkill kits (33.4x6.35 sched 160) I had only managed to bend that stuff twice, and both were hits so hard that I was sure the mounts were gonna be torn away from the chassis or something. I just went up to the next size tube to get a bigger weld area at the ends, and a little bit more strength can't hurt, the weight difference is pretty negligible..

Scott wrote:Do you know of any links on the internet that give sizes available? Every time I try and search for tube I don't get anything useful.

go to onesteel's american site onesteel.com (no .au) and it has a big PDF you can download with all the sizes listed..

Wendle wrote:

Robbo wrote:Don't be a SMARTARSE if you don't want sensable advice don't ask!!!!!!!

WTF?!?
I didn't ask you for any advice ROFL

SHS and RHS dont look as nice and weigh more to get those strength gains

ROFL @ carlton.

I do not have an affinity for box section. Despite having seen whole buggies made from it

Cheezy4x4 wrote:Just a question, how well do those bushes flex.

they seem pretty good. I put the front links in, with the chassis on stands, and a jack holding the front diff at ride height, no coils in, I stood on one hub and pushed the rotor striaght down to the ground with hardly any resistance at all.. I only weigh about 70kg, so I think with the weight and leverage of the wheels and tyres mounted, it will have plenty enough movement for me..

Mal Leslie makes some realy strong rectangular section 25 x 50 for GQ/Us.
Seen on many Comp vehicles, never seen a damaged one yet.
You can jack under them too,(i have)

He also has the adj drag links and steering links etc
03 9459 2859

Bazzle

Spot on Bazzle we run his gear under ours top rear arms front steer arms lower rears and if we break any of these the broken arm will be half the problem.

bj on roids wrote:
SHS and RHS weigh more to get those strength gains

What is your criteria for working this out?

SHS is a more efficient section than CHS based on a strength/weight ratio.

This is one of the jobs I have to do soon. Looking at several options. Trying to find a source of 7075 Aluminium bar - no luck so far.

If I cant find 7075 Al (or too much $$), will probably use hardened and tempered 4140 (chrome moly) seamless pipe.

Strength wise, bending strength is main criteria, and for this shs or rhs would be better strength/weight than plain carbon chs/pipe. At same wall thickness and mass/metre chs is bigger in dia and section modulus is close to that for shs, but yield strength of most chs is 200MPa (some 250MPa) whereas shs and rhs are mostly 350MPa (450MPa for Duragal).