As a previous poster mentioned it's crazy when dealing with different companies. What I found really weird was first understanding that 3/0 is thicker than 6/0 which is thicker than 8/0 OK, but when one 6/0 is much strong than another manufactures 6/0 is just plain weird. These days I am unwaxed UTC fan. The article that was referenced right at the beginning of this thread is worth the investment in time to read. If you are serious about you question, you will read it.

Rick