×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

High temperature stainless steel tube with thin wall

High temperature stainless steel tube with thin wall

High temperature stainless steel tube with thin wall

(OP)
I am finding it difficult to source 309 or 310 stainless steel tube with wall thickness less than 1.5mm (0.059") for outside diameter 15-22mm (0.56-0.866")

Used in a high temperature application (800C) formed into coils. Environment is low pressure steam and air.

So far I have only found schedule 40 pipe which is too heavy to be bent into coils.

I have done preliminary work with 316 ss to prove priciple but difficulty was cracking in the pipe.

Anybody know of source of 309 or 310 thin walled tube?


Many thanks

RE: High temperature stainless steel tube with thin wall

Have you considered 321 and 347H as alternatives?

RE: High temperature stainless steel tube with thin wall

(OP)
Problem seems to be getting tube in 316 or 304 off the shelf is no problem. Anything else is a special production run which would be in tonnes farher than a few lengths.

Unless there is existing industry demand such as exhaust pipes which dosnt go below 1". I need less than 3/4.

I'm sure ther is some out there. Finding it is a problem.

Thanks

RE: High temperature stainless steel tube with thin wall

Not knowing your specific application, I can only say that generally tubing is easier to bend with greater wall thickness. It prevents excessive deformation, thinning, and cracking. Just a thought.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: High temperature stainless steel tube with thin wall

(OP)
I would imagine thicker walls would enhance the structural integrity of tube when it is bent however it also increases the forces to bend tube.

In any case the vendor I have been using to make up coils puts a limit of 1.5mm wall thickness for the coils I need. I am not sure of their process but so far I have been satisfied with their work.

Another vendor may be capable of coiling thick wall tube but so far I have not had any luck.

Coils are 230 mm dia. with a 19 mm o.d. tube.

RE: High temperature stainless steel tube with thin wall

321 is easy to find off the shelf. 347 less so. The H grades are hard to find.

Never looked for 309 or 310 but 5/8" tubing should be available.

Alloy 600 definitely is available and might be worth considering too.

There are re-draw operations out there who will draw down larger tubes- usually for a hefty price and for a minimum order in the hundreds of feet.

RE: High temperature stainless steel tube with thin wall

Try McMaster.com ?

You can get .028" wall 316 and 304 from 5/8" down to 1/16". Plenty of other wall thicknesses also, but sizes can get scarce.

RE: High temperature stainless steel tube with thin wall

310(S) is readily available here (NL) in tube form, but 321 is harder to get, opposed to USA/CA maybe (as moltenmetal indicated).
I believe each continent has it's own 'typicals' (the germans e.g. may easily supply you 316Ti, which alomost equals 321).
For piping, 321 usually comes in dual certified 321/321H, Id reckon that may be the case too for tubing, but you'd have to check. We usually get 321 tubes from the American continent.

RE: High temperature stainless steel tube with thin wall

How do you dual certify something as 321/321H? It either has high carbon, or it doesn't...is there something weird in this spec? Does the H mean something other than high carbon for creep resistance? I'd often wondered how that worked with a Ti stabilized grade.

316/316L dual certified, because you can have the strength of the normal carbon grade while still meeting the low carbon spec., but you can't have 316/316H dual certified.

You're right about the regional variations in material- 316Ti is impossible to find here.

RE: High temperature stainless steel tube with thin wall

http://www.johnsontube.com/alloy/316.html
You can have 316/316H dual certified- 316H is definitely higher carbon than 316L but more so it has defined properties that need to be met as much as 316 just overlaps those properties.

RE: High temperature stainless steel tube with thin wall

Dual certified 321/321H is readily available for pipe [ASTM A312] and fittings [ASTM A403] (I think almost standard like 316/316L).
Flanges are more difficult to obtain in 321/321H, but Ive seen them on a recent job.
Tube I dont know of, but reviewing e.g. A213 I dont see how they cant be dual certified, from a chemical composition point of view

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources