Americans use kcmils or MCM for all sizes larger than 4/0 AWG. The smallest kcmil size is 250 kcmil, 127 mm2. Question for the American members, is kcmil used much outside electrics at all?
I'd never seen kcmil or MCM used anywhere except for commercial electrical power cable. Everyone else uses "normal" units.
If you do a google search and start filtering out electrical terms, you see the hits go down and down and down until there are only a handful of sites left, and then only because of the way they typed some of the key words: http://www.google.com/search?hl=en&lr=&q=kcmil+-electric+-awg+-cable+-conductor+-copper+-lugs+-crimp+-wire+-splice+-%236awg
One thing I have noticed over here, is that Automotive wire, in the heavier sizes, (for them over-powered Car-Audio systems) is sold in #8, #6 and #4 sizes. Unusual in a place that uses metrics.