Thin walled closed end tubing

Any decent TIG welder who works in sanitary Stainless steel can make them up for you.

You form a hemi-sphere of the required size in a press and weld it on the end of the tube. Some back-purging and post weld passivation and "shazam" all done.

I could knock out a pile of them in a blink.

I would start by calling Uniform Tubes. It's going to be a special order with a long lead time and a large minimum order. But they do stuff like that routinely. Tell them you want to 'deep draw' the items in question.

Jim

You might look at centrifuge sheilds (or tubes), for an off the shelf item that might work and not require a gigantic expense, custom manufacture, etc. A quick look shows several in stainless, though magnetic or not is not mentioned in the ones I've glanced at. Call up the companies and ask. Drawing may mean that the wall thickness is not uniform, if that matters to your application.

Another approach would be to sputter over a test tube, or other suitable substrate, which you might find facilites on-campus for.

How many do you need? Years ago I made something very similar by spinning tubes over an appropriately shaped mandrel. It required a number spinning/annealing cycles and finally welding a round patch over the remaining opening. The tubes we used were about 3/4 in diameter and had something like an 0.020 wall thickness.

Do they have to be stainless steel? I was wondering if cigar tubes might be an almost perfect size for your requirements.

A butt-weld cap welded to a short piece of tubing is a possibility. See McMaster p/n 44935K42 for an example of a

Ned Simmons

As someone else mentioned, many centrifuges use tubes like this - cruise the undegraduate chemistry labs and see what's available. However, if you really care about them being nonmagnetic I bet you will have to have anything you wind up annealed. Deep drawing or just forming tubing will work the stainless enough to leave it somewhat magnetic. You might want aluminum instead.

-- Regards, Carl Ijames carl.ijames at verizon.net

I've tried several websites, but I ***KNOW*** that I have seen something exactly like this. In some woodworking supplies catalog they sell stainless bud vases for incorporating into wood projects. A little tube, closed at the bottom and with a small flange at the other end. I can't say whether they are a non-magnetic SS or whether they are exactly the size you need, but they are cheaper by far than anything you could get made on a one-off basis. I'll keep looking and reply again if I find them.

-- --Pete "Peter W. Meek"

--Try finding a company called Zero; they specialize in deep drawn parts; maybe they've got an off the shelf item like this??

Thanks for the suggestions, guys. I've managed to find a supplier and I'm waiting for a quote.

......Andrew

Who did you go with?

What level of magnetic moment are you trying to go below?

Jim