Steel tube for bar work

[crispo]

Hi there, sorry to start another post I'm sure its been covered off dozens of times but can't seem to find a definitive answer.
I have just acquired a shit load of steel tube, (46m+) it is 42mm tube and has a 3mm wall.
After doing some research online it seems like it may be scaffolding tube?

Now what I want to know is this suitable for some rock sliders, rear bar, etc..... My truck is my daily driver and I am far from a big time 4x4er, just starting out with club days etc. My truck is relatively straight and would like to keep it that way if possible.
Would this steel tube be ok to use as I have a shit load of it now or am I better to forget about the idea.... Any feedback would be greatly appreciated.
Cheers Chris

[mudlva]

Simple answer. Yes.

[Checkerhead]

My roll cage (built to ORANZ rules) is built out of "NB32" which is inch and a quarter nominal bore seamless steam pipe. It has (from memory) a 42.2mm OD and 3.2mm wall.

So based on the similar dimensions and assuming that they are both close enough to mild steel I would say that your pipe will be perfect for a bit of bar work and some sliders. Should also bend reasonably well in the cheap benders due to it's steam pipe-esk dimensions (they all come with dies for steam pipe)

Good luck.

[derk]

if its scaffolding tube its probably galvanised tube so it'll be ok for general shit but don't go doing anything structural like a roll cage with it galv doesn't weld very well and it also gives off evil fumes so don't go breathing any in while your welding

[crispo]

Aw rite oh, cheers guys. Its painted red at minute so don't know if galvanised or what. Il run a piece down to a guy who I know builds 4x4 cage etc in Papakura and see what he reckons about it. Just be nice to put it to some use cause can't afford to go and buy the good stuff for some time.

[mudlva]

After grinding where you want to weld.
Acruatly mark where the junction is between the two meeting pieces. Weld onto the flat service first then grind the weld back. This will burn any zinc and leave it ready to take a good weld.
As said above the fumes are a bit nasty so use plenty of ventalation.

[wjw]

If it's red, it could be the stuff they use for sprinkler systems

[cpt kernow]

And if scaffold pipe, then isn't this seamed? S good for most stuff but not a cage.

Just grind the galv off where you're welding.

[mudlva]

Nzfwda cage rules are
250 grade medium wall black pipe

Doesnt mention seamed or seamless

Does say black pipe. Dont know what the differance is between black pipe and galv in the structual since

[crispo]

Yea quite confident it is steam pipe after seeing more of it. Just got to get a good little Mig welder and pipe bender now to make some stuff.......

[mudlva]

Yea quite confident it is steam pipe after seeing more of it. Just got to get a good little Mig welder and pipe bender now to make some stuff.......

Re the mig. As big as you can afford. You need heat to bite through the galv and little migs just end up overloading.
imho 175amp or bigger.
im now welding with a 250 unit and burns the galv off nice.
as said above the fumes arnt good so use ventalation

[De-Ranged]

Nzfwda cage rules are
250 grade medium wall black pipe

Doesnt mention seamed or seamless

Does say black pipe. Dont know what the differance is between black pipe and galv in the structual since

In the tube its self no difference the galv is just a covering.... what I would expect is you wouldn't be allowed to use it due to the issue of weld quality, I've built alot of stuff in galv for jobs where corrosion is an issue and with a little timing you can get a good looking weld (mudlva is spot on you need more voltage to force the arc through the galv) catch is if you grind them back they are full of porosity and they haven't "wetted" the edges into the parent metal like a normal weld, this means the edge of the weld is weaker .... I wouldn't do anything structural with galv
Oh and don't think its all good because you have ground the galv off, if your getting a good weld with full penetration your just going to pull the galv from the inside of the pipe lol

All good for bumpers and that sort of stuff, I wouldn't use it for a cage that you intend to test out lol

Oh and if you do weld this stuff use ventilation and if you can find one a mask (I use the pink filters, sorry can't remember what rating lol) there are some nasty heavy metals in this stuff that you are turning into a gas.... oh and the old wives tale of drinking milk afterwoods is just that a tale lol it doesn't do anything

[snatch22]

prolly better drinking milk before hand ...have seen roll cages in dirt cars made out of galv and black pipe and out of the rolled cars i've seen only the black pipe bend or kinked