I found the product codes for silver tube didn't give any idea of the sizes tube wall thickness etc, so I made a credit card sized visual aid in Corel Draw showing me all the different sizes available, I've found it useful, so I thought I would share it here.
Each tube product is listed as a picture of the cross section, Product code, Outside diameter in mm and Inside diameter in mm.
eg (picture) RSA 005 5.3 2.6
If you scale it to print out the same size as a credit card, the sizes are accurate,
Note - While all members of the Cookson gold forums are welcome to print it out for personal use, I retain copyright for all other purposes.
If you want to use it elsewhere email me first.
Cheers - Dave