How to ID seamless tubing

[widlin1]

Last week I bought a band saw from a friend of a friend who is a fabricator/welder and I asked about seamless tubing. They gave me a piece of scrap that they were pretty sure was seamless based on the job it was for. The tubing is 2 inch OD, .065 wall T304/304L. How can I verify that this is seamless? Can anyone decipher the writing on the tube:

UNITED LWT 2 X .065 T304/304L SA249/A249/A269 NDE HT#31230 OP#714/575 01/08/09 15:58

Thanks

Jeff

[widlin1]

I think by doing some googling that it is welded

Jeff

[Mongo]

SA-249/A-249 is Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes
A-269 is Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service

So the tubing is welded.

[widlin1]

Thanks Mongo, I guess I will have to order some seamless.

Jeff

[Mongo]

What are you using it for? Center fire can? Its should be some pretty good stuff, if I was at work I could look up the specification for you and find out what the inspection level is. If it is inspected with full radiography then it could be considered as good as seamless. Problem is I will not be back to the office until December.

[LavaRed]

For all my suppressors, I've gone with solid bar stock, hollowed out.

[SRM]

You could use mechanical tubing but small sizes hard to find and expensive. solid stock would be way cheaper.

[Baffled]

Without the writing on the tube, you can usually ID welded tubing (even if there is no obvious weld present) with a good telescoping bore gauge (cheap). What you do - when the weld takes place, it almost always warps, very slightly, out of round. DOM (non-welded) tubing usually has an ID that is amazingly consistent, regardless of the angle that you place the bore gauge. So place the gauge in the tube in one orientation, like 12:00 to 6:00, and measure. Then, rotate it 90 degrees to 3:00 - 9:00 and re-measure. Welded tubing will have much larger variances depending upon the orientation of the bore gauge, maybe 0.012" in a 1.25" ID, whereas the same tube in quality DOM will be closer to 0.002" regardless of the orientation of the gauge.

Additionally, the interior finish in DOM will almost always be much finer, and the ID consistency end to end will usually be better. That's been my experience. You can make a fine can from welded tubing, but if there's a choice, pop for DOM. When you consider the stamp cost and overall effort, it rarely pays to take short cuts. The DOM is worth it, IMO, at 3X the cost of welded.

[widlin1]

Mondo, if you remember when you are back in the office I would like to have the specks on the tube. A project at work has been hogging most of my free time so I doubt I will be much farther with my project then I am now. I got the tubing with the intention of using it for my 50 caliber project based on her 458 socom brass necked up or 50 Beowulf brass with a .512 bullet seated in it. I expect to be using approximately 30 grains of powder with a 16 inch barrel.

Thanks for everyone else’s advice as well

Jeff

[Mongo]

Mondo, if you remember when you are back in the office I would like to have the specks on the tube. A project at work has been hogging most of my free time so I doubt I will be much farther with my project then I am now. I got the tubing with the intention of using it for my 50 caliber project based on her 458 socom brass necked up or 50 Beowulf brass with a .512 bullet seated in it. I expect to be using approximately 30 grains of powder with a 16 inch barrel.

Thanks for everyone else’s advice as well

Jeff

It will be a while until I'm back, hopefully you;ll learn to spell my handle by then

[widlin1]

Thanks sorry about the spelling

Jeff