Custom Strut Brace... What kind of steel?

[Andrew357]

I am getting a custom strut brace made up for my car for a little project I have going on and I've finally found a place that is willing to do the job for me (http://www.scottmetals.com.au/index.htm)

The only problem is that I don't know what kind/s of steel I should be using that would be best for my situation. I'll need a steel that has resistance to bending, compression and torsion.

I've had a look on various sites (Bluescope, Atlas, OneSteel etc) and they list various Grades of steel in various shapes (sheet, i-beams, tubes, reo bars etc) but I can't find any information as to which grade of steel would be best for my application.

I've got the dimensions of the brace that I want but I don't know what to make it from. Does anyone have any knowhow on this situation?

[Foss]

I'm thinking you'd be best talking to an engineer. I guess that a high tensile pipe/tube would be suitable, that stuff has some hardcore strength, but I'd imagine there'd be a specific minimum diameter and wall thickness for what you want. But then even some aluminium is fairly strong (think scaffolding), and has the advantage of being light weight, which HT steel is far from being. Bohler Uddeholm has a fair range of high tensile stuff, and Ullrich or Capral Aluminium might be able to sort you if you go the ally way, but I'm not sure whether any of those sell direct to the public.

All in all, though, I say an engineer would be the best to recommend an appropriate material.

Why custom, anyway, as opposed to just fitting a ready made one?

Edited March 2, 2010 by Paradigm

[Andrew357]

Yeah, I have been recommended an Engineering place which I might take the idea to first before heading to the steel place.

Custom because with the upcoming installation of my TRD Supercharger, I need a strut brace that will clear the pulley/belt setup. Unfortunately, the standard brace doesn't and neither does the UltraRacing ones (which is a shame because the UR brace was very good!). The only one that I know of that will fit (thanks to SupaTouring) is the TRD Strut brace for a Gen 1 CamrySolara from the states. But they are very hard to find.

Anthony (STYLSH) has lent me his and i've fitted it to my car in order to get the right dimensions, it's just a matter of getting one whipped up.

[SuperDave]

You don't need high tensile steel as the strut brace (by it's very name) is a compression member. To design for bending and compression you need to know how much force is going through the upper mount; there is no torsion (bending) through the bar itself to cause any worry.

The only stuff to look at would be round, oval or box. Round and will look much more professional; I sections won't come in a small enough depth. Due to the limited movement within the brace the common grade 300 will be fine. The 300 is the yeild stress in MPa.

Could use Al, but because it's yield stress is about 70MPa you'll need to select a thicker wall than you would steel.

[and1]

Box section ftw :P

[Andrew357]

Handed the bar over to an engineering place today.

They said they'd take care of everything. So i should hear from them in a few days. I won't name the company till after the work is done.

[The Last Streetfighter]

So what are they using?

CrMo?

[Andrew357]

Some sort of steel. I neglected to ask for specifics.

Edit: I did mention rustproofing so it will be Zinc plated

[Andrew357]

Finally got my strut brace done.

First thoughts:

- Dimension wise the bar is exactly as I need it, so the guys I took it to knew how to replicate something.

- Heavy, much heavier than any strut brace I've felt before. Probably because of the bar they used to affix the 2 end brackets together. Flat bar, 40mm x 10mm, Grade300 steel. In any point on the brace the steel does not go thinner than ~6.1mm

- Disappointed as to what I got for the price I paid. I still need to powdercoat/zinc plate it for rust proofing purposes. I guess that is the price you pay when you take it to someone you don't know based on a friend's recommendation.

[CHA54]

hahah! That would weight a ton made from flat bar

[Andrew357]

I'll give her a weigh when I get it back from a powdercoat on Monday afternoon.

Getting it done in a simple gunmetal finish.