[ Ref. 090501 MMDigest, "Seek Source of Brass Tubing" by Don Teach

K & S Engineering, the company that makes the brass tube for sale
in hobby shops throughout the country, does an excellent job of
custom cutting at a very reasonable price.  Their tubing is very
precise and everything about their operation is professional and
reasonable.  They actually shipped my orders faster than they quoted
and I never had a problem with quality.

You do need to order several thousand parts if they are small and
you want a good price.  I had 3/4" long tracker bar sized nipples
made and I think they cost about $.03 or $.04 each in 5k quantity.
Visit http://www.ksmetals.com/ 

You can save a lot of work getting tubes cut to length if you want
to make sleeved reducing nipples.  K & S might even be able to make
one-piece reducing nipples if they have a way to swage them.  If you
make them by sleeving, soldering is nice but it will get very boring
after a few hundred and care should be taken to avoid exposure to
heavy metals and flux, especially if you are using lead solder.

K & S tubing is telescoping and fits quite tightly.  Thin CA glue
would wick in very easily and make a tight and long lasting seal.
CA glue is toxic too but it would probably be easier to use this for
making thousands of nipples.  I have glue dispensing machines that
I have both bought and made.  These can make it a lot easier and safer
to glue with CA glue and not get yourself stuck to the parts.  Glue
dispensing machines are readily available surplus on e-Bay.

I have a few thousand 5/32" x 3/4" nipples that I would sell cheaply.
I might be able to come up with a gluing machine to lend to someone
wanting to make a batch of reducing nipples.  I also have some rack
gears of Teflon that might be useful in making a gluing fixture that
CA glue would not stick to.

If you do order tubes from K & S and you want them to slip together
easily, you need to specify that you want them fully deburred.  They
generally will only lightly deburr them in order to maintain tolerance.
For a non-critical fit it might be best to deburr them more rather than
less.  I needed a reliable light press fit and did not want dimensional
changes so I did the final deburring myself and watched it very
carefully.

Best regards,
Spencer Chase