Don, I get brass rod and tube (in 6-foot lengths) from MSC Industrial
Supply.  They are a machine shop and maintenance supplier with a very
wide catalog and very fast delivery.  They are nice enough to supply
small stock pieces of various metals, plastics, and rubbers.

  MSC Industrial Supply Co.
  75 Maxess Road
  Melville, NY 11747-3151
  http://www1.mscdirect.com/cgi/nnsrhm 

Stan Harrison