We often get asked where to buy Aluminium extrusion.
This really depends upon where you live. OpenSimRigs can supply 8020 to anywhere in Canada at a competitive rate.
Europe
http://www.boschrexroth.com/corporate/en/index.jsp
http://www.smt-montagetechnik.de/produkte.htm
http://aluminium-profile.co.uk/
North America - Aluminium Extrusion
Example pricing for ONE aluminium cross brace from two aluminium suppliers
- T-Nuts, 12" of 1530 Profile, Two L brackets, t-nuts & bolts, $17.80USD
- 8020.net, 12" of 1530 Profile, Two L brackets, t-nuts & bolts, $30.57USD
The largest supplier in north America is 8020.net but the pricing is high!
eBay off cuts
http://stores.ebay.com/8020-Inc-Garage-Sale
Minsumi in the USA is a good alternative to 8020.com
http://us.misumi-ec.com/vona2/result/?Keyword=Extrusion
McMaster in the USA is another great supplier.
http://www.mcmaster.com/#80-20-compatible-t-slotted-framing/=11g5rsy
If you are looking for small section extrusion for accessories, then OpenBuilds.com offers some great extrusion and gussets.
http://openbuildspartstore.com/v-slot/
Amazon.com