We just got these very nice, 9 inch brass tubes (9 inches in length, 1.5 inches outer diameter, 1mm thick).   You can stand on these and they won't bend at all!  These were custom made for us and we are very excited that they have arrived.  They are very smooth and have a lovely color - these (the 9 inch tubes) have a more matte finish than our previous tubes, and have a single layer of lacquer for protection from oxidation and enhancement of appearance.
 
Note: These are genuine brass, and like all brass items we believe the tube may at some point may need to be re-finished.  Or you could remove the lacquer and finish with whatever you like (or nothing at all!) But we think they look great the way they are now!