What grade of stainless tube?

[bigbadbugga]

I need to run some car length 38mm(1.5mm wall) tube for my scooby bug project, I have been looking on ebay for the tubes and bends. (sold as exhaust tube)

They seem to be available in grades 304 and 316, what do you guys think would be best?

Bearing in mind they will be carrying coolant upto around 100 deg/c.

What are the differences between the two on terms of strength and corrosion resistance? and is there anything I need to know about welding them (tig)?

 

[hotrodder]

No difference with regards to strength, 316 has better corrosion resistance, specifically in chloride environments hence it being often referred to as 'marine grade'. Either will work fine

loads of threads on welding the stuff (pretty much every exhaust topic), will need to be purged with argon, use 316L wire. If the fit up is spot on and pipes will be very well supported could weld autogenously too

Ebay typically an expensive source for bends and the like. 38mm, 16 swg 90* bends around £4 something each from a stockholder

 

[bigbadbugga]

Thanks.

I'll google for local stockholders then, ebay search was just to get an idea of what material is available really.

 

[hotrodder]

Try Aalco (no idea if there's a branch near you but they're nationwide). All stainless one option for mail order (iirc there's a £50 min order). No doubt google and the forum will get you more options.

One of the cheaper 'non metals stockholders' is ojz engineering (exhaust fabrication). Thinking more for straight lengths if it turns out you need just over 1 length for example as they sell by the metre

 

[bigbadbugga]

Aalco was the first place I looked after your first reply, there is one on the dock road in Liverpool

No prices online though, so I'll ring them tomorrow. It will help now I can sound like I know what I'm asking for.

 

[jimi_boom]

If i were you i would avoid 316 its more exspensive due to the industry it was designed for (the mediacl industry)

if its just for cooling pipes i would go with 304 as its likely to be slightly cheeper and you wouldnt miss the extra corrosin resistantance that 316 provides,

Only my opinion though