Is my stainless steel exhaust actually stainless steel?
 

It sounds like a silly question, but I always try put a descriptive title!

I've just bought a T304 stainless steel header and up pipe. The tubes are non-magnetic but the flanges are magnetic. Is this usual? And is it ok to weld two different types of metal? A mate reckons it isn't.

Cheers in advance,

Neil P

Stainless steel is a mixture of steel and chromium so is magnetic, your mate is correct it isnt a good idea to atempt to weld two different metals

Oh, the tubes didn't seem to be magnetic! I'll have to check again later.

Cheers for the reply :thumb:

Low grade stainless is magnetic, some stainless are not magnetic, its also not uncommon for some stainless systems to have mild steel flanges as they are so much thicker they won't rot through.

T304 will surface rust, but won't rust through, can't remember if its magnetic though!

You can weld two different materials dine as the welding changes the material properties anyway!

Simon

304 stainless is 18% chromium and 8% nickel - is is magnetic but pretty weak. Stainless sinks are commonly made of 304 type material - you can feel a pull with a magnet - but it will not clamp on like it will on your fridge :D

you can weld mild steel to stainless steel using stainless rods or wire depending on the process used.

stubb's