Hi,

I'm just putting an order together for steel for my chassis through parkers steel and just want to check I've got the right stuff.

Book: 1in x 1in 16swg RHS steel tube
I've chosen 25x25x1.5mm wall ERW semi-bright tube

Book: 3/4in x 3/4in 16swg RHS steel tube
I've got 20x20x1.5mm wall ERW semi-bright tube

Book: 3/4in 16swg rounf tube
I've got 19x1.5mm round ERW

Book: 16swg sheet steel
I've got 1.5mm BS EN10130 CRGP which I found under "Black carbon sheet & plate/plate/cold rolled general purpose"

...and some 3mm sheet of the same type as the 16swg (which is relatively expensive).

Does the specifications seem ok to everyone?

Thanks,

Mark

Its just a more modern terminology, just dont use the round tube for your wishbones, ERW is not up to the job

I think you,ll find that you actually want the RHS (rectangular hollow section) rather than the ERW (Electric Resistance Welded) The ERW has a welded seam that can weaken one side of the tube iirc . I,m pretty sure someone more qualified than myself will drop by and confirm .

erw is what nearly everyone uses for the main chassis parts. it does have a seam inside but thats not such a major problem.

when you say RHS you tend to get ERW. RHS just specifies the shape, not the method used to form it.

RHS=ERW=RHS

Square and rectangular section is all ERW in my experience, I don't think anyone does anything different. DOM and CDS are usually round or oval section. CDS is what you want for wishbones.

Thanks everyone.

CDS stands for cold drawn steel doesn't it? On parker's the closest I can find to that description is "Cold Formed Hollow Section" but the 20mm diameter stuff (21.3mm) has 3mm wall thickness which seems a bit thick to me. Does that sound like the right stuff to use? The only tube with a wall of 1.5mm is the ERW.

Regards,

Mark

[Edited on 20/10/04 by dern]

I would use the 3mm wall thickness
Rob

RHS is not available in 1.5 wall thickness.

The book terminology is wrong.

ERW square tube is really the intended material.

Apologies for mentioning this on numerous occasions....

quote:

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Originally posted by dern
Thanks everyone.

CDS stands for cold drawn steel doesn't it? On parker's the closest I can find to that description is "Cold Formed Hollow Section" but the 20mm diameter stuff (21.3mm) has 3mm wall thickness which seems a bit thick to me. Does that sound like the right stuff to use? The only tube with a wall of 1.5mm is the ERW.

Regards,

Mark

[Edited on 20/10/04 by dern]

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Where can I get 1.6mm thick 25mm box from?

My local fabricator can only get 2mm thick?

Cheers!

Thro' 20 years of metal buying.....

ERW....is really a process name and as Pete says is used for most (all?) square/rectangular sections....however the term is also applied commonly to sections of thinner wall thickness (e.g. in the case of 25 square less than 2mm)

RHS/box section....the term is usable for all sizes, but is commonly reserved for the thicker sections (e.g. for 25 square 2mm upwards)

CDS....usually for round tube

DOM.....as above, often considered as good as CDS (US racing bodies consider it equal for rollcages etc.)...some consider it better as the concentricity is more accurate.



[Edited on 22/10/04 by Alan B]

quote:

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Originally posted by Chris Green
Where can I get 1.6mm thick 25mm box from?

My local fabricator can only get 2mm thick?

Cheers!

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i would just ring another stockholder. I cant believe that no one sells it.

You are asking for the metric equivalent of what you want and this will not be available. What you want is 1" 16 gauge tube.

quote:

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Originally posted by Chris Green
Where can I get 1.6mm thick 25mm box from?

My local fabricator can only get 2mm thick?

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Cheers Mark,

However, Parkers only list a minimum thickness of 2mm for 25mm square section on their website?

Do they stock 16g as well?

Cheers,

Chris.

I'm pretty sure mine came from Parkers so they certainly used to!

James

quote:

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Originally posted by Chris Green
However, Parkers only list a minimum thickness of 2mm for 25mm square section on their website?

Do they stock 16g as well?

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oh yes. I see.

I was looking in the "Black Carbon Steel Hollow section" section.

Cheers!

Chris.

quote:

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Originally posted by Chris Green
oh yes. I see.

I was looking in the "Black Carbon Steel Hollow section" section.

Cheers!

Chris.

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