About SWG

Hmmm... it seems that the AWG and CSA standards are much more common. There's a good table of AWG current ratings on PowerStream's web site and there's a cross reference between AWG, CSA, and SWG, with current ratings and derating factors, on Farnell in One's web site

I hope this helps.

Wire Guage Conversion
http://home.datacomm.ch/hb9abx/wire_gauge.htm

It is a table 4 equivalent other guages.
Below the table are a lot of link 4 much more info
In addition you can find much more information
Regards