Hi all

Trying to find aluminium (or steel if I must) in sizes where one bit fits neatly inside another and can be locked in place with simple clamp - think bike seat-tube into frame, but bigger, say outer tube 45 - 60mm dia, 4 or 5mm wall, if ally, 35 - 40mm, 3mm wall if steel.

Ideally, from an aesthetic point of view, i'd prefer oval tubing say 60mm x 30mm OD in ally but this seems like hens teeth...

My google fu isnt delivering today :(

Any ideas?