Thread: What metal do I need

Originally Posted by miles and jules

Hi guys...my first post

Just got some sheet metal today that is 1.2mm thick. I asked the guy if he had any that didnt rust...so he said this zinc/steel sheeting didnt and that it wasnt a zinc coating either but a mix.

So I am wanting to know what this is properly called. I'm wanting to know so i can try and track down some 6.5mm tubing in it.....also if you have any suggestions of where to track this down, that would be cool ...we are in brisbane-ipswich area

Thanks
Miles

Hi Miles,

Any chance of a picture(s)?

Well there's
-Zinc anneal
-Zincalume
-Galvabond

You won't get 6.5mm tubing in any sort of those. You may get it Copper or Stainless

Hi...wow that wa quick ... thanks for the replies.....I cant send a picture as the metal is at our shed....

We could probably go to 8mm tubeing would that be possible in one of these metals
-Zinc anneal
-Zincalume
-Galvabond

I think it might be zink anneal......it was about $50 for a 2.4mx1.2 m sheet. Copper is problematic as it reacts with latex foam(which will be covering the metal.....I guess we could seal it with epoxie or something.

Stainless is a bit of a nightmare to work with for us...we need to tap it aswell. Aluminium is not tough enough. What else could we use?

I don't think you'll get anything that size in steel. What about Aluminium?

Hi ...Yeah we tried alluminim today(are there different grades of aluminium?)...but we need to tap it and put a screw in it and it just threads when we tighten it. So we are really after any mild steel-like tube that we can tap easily that doesnt rust and isnt copper.

It would be really great if we could get tube in this same zinc stuff we have in the sheeting.

These guys look like they have small sizes in stainless http://www.spec-net.com.au/links/link141.htm

I haven't seen galvinised tubing that small in any of the trade catalogues that I have.

If you can divulge what application you are wanting to use it in then maybe the collective knowledge here may be able to give you a bit more advice

There are heaps of grades of Aluminum. Google it and you will find them, mainly in the 6000 series, but I think there is also at least one grade in 7000 series. ( I got some to make a top triple tree for a motorcycle)

Welcome Miles, hope you enjoy yourself around here.
I'm a bit confused about what you're trying to do...tap a thread down the guts of the tube, or on the outside; or tap a hole you've drilled into the tube?
Sounds like you might be breaching any rust-proof plating anyway, by adding a screw or bolt. Can you use pop rivets or something, so there isn't the chance of cross threading? They are removable if need be.
Otherwise is there any chance of finding what you need in plain old mild steel then coating it somehow?

Cheers,

Hi Andy
Yeah we are taping a hole in the side of the pipe so we can turn a screw and lock aluminum wire inside the tube by turning a screw on the outside. The thing with this zinc sheeting we got today is that they recon it wont rust even where we cut it. So it seems like it isnt a coating but its all rust proof.....Which is cool for us. It would be cool if we could get it in tubing. We will give the same place where we got it (hands steel)a call and see if they have it in tubeing but i think they said they only have it in sheeting. yeah...We might have to try mild steel especially if we can get it in the right size.

What size is this screw? You might be better off brazing a bush onto the tube then drilling and tapping a thread. Any tubing in that size will have a very thin wall thickness and you will most likely strip the thread after a couple of times of loosening and tightening it.

Tapping a hole in the pipe wall is an additional constraint on your choices. For best performance, the pipe wall should be about the same as the thickness of a nut for the same size screw. I don't think you'll find a combination of such a wall thickness with your proposed pipe diameter. Such a material would be called a "hollow round bar" - likely available in limited materials, and still maybe not in your needed combination.

How does the sheet metal get into the act? Pipe attached to the sheet? Pipe stabilizes Al wire? A possible solution could be to attach small Al blocks of appropriate thickness to the sheet via pop rivets; hole for wire parallel to sheet. Blocks located close enough to preclude wire buckling. Threaded hole in Al block perpendicular to wire. Use stainless steel screws. For best purchase of SS screws in Al, make pilot hole for threading at root diameter of screw thread (i.e. 100% engagement), not normal tap drill for such taps in similar materials (usually only about 65%). Note I'm only guessing about your application.

Joe

Hi
we tapped the 1.3mm thick sheeting we got today and it was definatly tough enough for what we need, so as long as its no thinner it will be fine to tap. the screw size is 3mm. We tried a 6.5mm tube in aluminum and it was perfect size but as soon as we tightened it and unscrewed it a few times the thread was gone. So if we could just get it in something like the zinc/steel sheet we got today only in a tube we would be happy.

Why not give stainless a go, it's not all that hard to tap especially at that thickness. You just need to use plenty of lube and back the tap out after every half turn to crack the swarf.

Hi
Yeah there is a place on the way down the coast that sells stainless at this size so we might have to give that a go.

Thanks
Miles