Small precision tube

I was just going to suggest that you should look at hypodermic needles, I have completed projects involved in the manufacture of them and as they are made in huge quantities the price should be minimal.

If you need a plastic tube with precision id diameter there are many types around, but the od would be large compared with the id...

I'm not sure what your problem is with the hypodermic tubes?

John.

OD tolerance on your tube is tight. Recommend you look at all the manufactures of needle tubing. See if they can meet the tolerance. Best I see is +/- .01 mm.

It is a long story, at first the tolerance was 1mm+0/-0.1mm and not many companies responded positively. 2 out of 20 I contacted worldwide.

The integrator had problems and revealed the real tolerance they need, woof!

Additional to mine and ozzb's posts above.

Why do you need this tight tolerance? is it possible to reduce the tolerance or to redesign whatever it is used for?

John.

try small parts inc out of miami lakes fl you just might find what you need

dragonbreath

Thanks, I was only thinking of them as a distributor.

Hi,

these tubes are drawn like wire to the final diameter.

If you order your material to be drawn in a new drawing-die (diamond or carbide) made to your tolerances this will give good results.

I had a similar problem with a high accuracy brass wire (0.1mm dia, 0.001mm tolerance in diameter and roundness). This approach worked pretty well but we had to buy around 100kg of the wire.

RHABE

Thanks, I will ask the tube manufacturer what type of die they use.

Hi all, thanks for the replies.

As many posters, I forgot a crucial piece of information.

The material for the tubes is 304L, drawn, welded and ground.

It is then electropolished to ensure the surface finish.

The reason for this precision is it is press fit in magnetic material.

I can't change the specs for the OD tolerance.

Hello dear friend,

Try availability in your surrounding area is the easiest and best solution.

While developing prototypes and models, we come accross so many critical components like this precision tube. But many times such parts are hard to find and due to time bound targets, we can not indulge and keep on searching. The quickest solution I could find in my life is 'make it your self'. Recently, We were in need of similar brass tubes of 0.91 mm OD X 0.45 mm ID X 12.0 long. We started making them inhouse and got rid off.

Try this if possible.

Local for this is not possible, north-eastern US is quite near in our Global Village, and tubes can be made there at +/-0.0001in.

Integration in in another part of the village, Taiwan.

To be able to go beyond +/-0.0001in is quite a feat and a very specialized job.

So far I got one promissing contact from this post, this is great!

A Taiwan based small hole EDM shop would a great thing.

Hi,

Could you please inform what quantity you need ? We will start taping sources like that. Moreover what are your tollerances on ID ? In case the required quantity is huge, probably extrusion will be the only way out. Ofcource you will have to grind the outer dimeter to maintain the sizes.

We need components quite often, where the hole sizes are less than 0.8 mm. Earlier we have been spending considerable time in searching the sources, but hardly any one could satisfy the need.

I need 500 ASAP, after 2K-3K yearly.

The ID tolerance in non critical and can be between 0.4 and 0.5mm.

OD tolerance and finish is the fun part.

The +/-0.0001in (+/-2.5µm) OD tolerance is available, but I need half that.

Have you tried contacting Microgroup (http://www.microgroup.com/)? They don't list your precise size in stock, but the tolerances are excellent, and they may be able to make the size you need. They've got both seamless & welded type 304 as standard items.

Thanks, they were contacted but did ''noquote''.

Advanced Grinding & Machine in Louisville Ky. makes parts as you describe. www.advanced-grinding.com . My first choice is to buy the id to size and grind the od. The tensile or hardness of the material has a lot to do with the other sizing operations, cross holes and or threading.

Bob 502-452-9851

Extruded or welded tube, that is the question. I have a friend that can help from Sandvik who can point you where you need to go. Let me know. Check out www.smt.sandvik.com The world leader in tube products pertaining to the biomedical field. I use a lot of tubing from these guys, so far so good.

Either will do, thanks for the lead.

I have similar items in stock and today we will measure them to determine if we need to resize the od.

Bob