No, steel structural members are usually described as the depth (actual) x weight/length, such as a C12x 30 is 12 inches deep channel section and weighs 30 pounds per foot.

http://www.structural-drafting-net-expert.com/steel-sections-standard-channels.html

http://www.engineersedge.com/structural_shapes_menu.shtml

Steel member dimensions do vary based on what specific section is called for. Also, they vary much differently than your example. That is because there could be a bunch of different sections for a specific designation. For example, the W12 designation comes in many different varieties, from the W12x14 up to the W12x336. The master source for all steel sizes, in the US, is the AISC Steel Construction Manual. This is what Engineers use to chose members.

Edited by bmcnyc - 13.Jan.2010 at 03:29