DO I really need DOM tubing for front crossmember?

Figure8... Stock Cars... Those are the Key Words!

 

Tubing not pipe dude.

 

^^^thanks, that bugs me too...pipe id. tubing od....but then there is exhaust pipe which is actually tubing

 

So is the zinc the only problem?
In the past ive been using galvanized steel plate, and before welding it i grinded the zinc coating off. I welded it with no crackling sound or white smoke. I still do this on occasions.

About the "black pipe", i sure might have misunderstood, here in Italy at either the steel supplier or at the bigger chain stores the steel we buy is fosfatized for rust prevention, and the treatment gives it a black patina.
This is done to any shape and type of steel, i.e. flat stock, square stock, round or square tubing etc....is this what you call "black pipe" ??

 

What we call black pipe here in the mid west and in the fabrication indusrty is plumbing pipe. it is low grade low tensile strength not to be used for structure.

It is not the zinc that em-brittles the metal it is the heat from the plating process. You can certainly use the plate and perhaps the tubing if you want just make sure that the tubing isn't pipe made for plumbing. It is not accepted by most if not all sanctioning bodies (racing) because of the damage done in the plating process. I did work for a boat dock company (steel and foam floating docks) back in the '70s that used all galvanized (zinc plated) material. Many if those docks that I welded together are still floating. I don't think that is a testament to the strength of the material used, but it is a testament to resistance to oxidation. Floating on a lake is nothing like being driven down the highway.

 

Right, that is exactley what i wanted to hear about the zinc-ed tubing/steel. Thanx.
So, how do you call the type of steel i was talkin about?...althou to be fair i dont even kno how we call it over here hahaha...

 

It sounds like you are just buying cold rolled steel that has some sort of a treatment or coating to keep if from rusting. If it is all covered with mill scale (looks rough and flakey) it is hot rolled, but if it is smooth it is cold rolled. old rolled stell will be closer to the actual size that you are buying like within .010 and hot rolled will be way off because of the mill scale as much as .125 off in some cases.

What do they call it at the supplier? I know, black iron?

 

Yep.

 

Which is usually special order and not easy to come by. We used to get that in sheet for some projects, doubly rare in tube and square forms.

Bob

 

Maybe not in Europe.

 

Here in the states, black iron pipe is el-cheapo and composed of varying quality steel. Beaner mentioned the thickness issue, seems other parts of the world call out their steel in different ways.

 

In my experience, most railiings and the like are made of schedule 40 pipe. This is not suitable for any critical automotive applications. Hopefully what you have is not pipe but some sort of EW mechanical tubing. I can't imagine risking my neck for $25 bucks worth of readily available stock.

If you need a source for the right stuff, call 610-929-3663 and Victor will ship you the piece you need UPS for reasonable cash. He keeps it in stock for me. There ain't no thrill like eatin' dirt at 80 MPH.

Also I only use cold roll for any additional chassis components along with pickled and oiled 10ga. for frame rails. The couple of bucks spent is more than repaid in finishing time and ease of fabrication.

 

Ah! Ok, expalination was perfect. Cold rolled deffo, i know the mill scale you talkin about and im not buyin that one, nor the oiled one, which i rarely see anyway.

As for thickness i usually get 3mm to 5mm depending on application. And i either buy from the steel supplier, which is actually also the producer.
Or i have a hook up at the recycling yard where i can get the unused bits from the big construction companies that get rid of it basically new (just weathered) and i only pay it a 4th of actual price for the same material.

Problem with the steel warehouse is i have to buy lenghts of tubing that are short of 14' and i dont always have either the need or the dough to do so, as 14feet of 4mm thick 2''x6'' (just an example) was costing me 80euros last year, and for a guy on minimal wages is steep when the same material is 50cent per Kg at the yard, and all it needs is surface rust wire wheeled off.

 

Our local steel suppy shop has a section where they put cut offs from various jobs they do. They call them "drops". We used to be able to look at them and pick out some pieces we could use but some idiot customer got hurt in there and sued them, so now NO ONE but employess are allowed in the shop. We have to peek in the garage door and kinda spot something that looks promising, then they will go pull it for us.

Maybe your local supplier has some of these shorter pieces laying around for sale at a reduced price.

Don

 

Just use an old driveshaft.......

 

Good steel, but I'd question the wall thickness of most drive shaft tubing for that application.

Bob

 

the chevelle one i used once was pretty think, i dont remember details

 

I actually asked, but reply was nope. My guess was they keep them for "selected" customers.
As for being allowed in, we are, we can bring our own grinder and cut the lenghts to fit our veichles, as not everybody as a truck with a 14' bed.

But thanx for the suggestion