Plain Carbon (C.R.) Steel
The Cold-Rolled or plain steel is the base material for many flat sheets. This material will definitely rust and is typically coated with some sort of finish applied to surface to hinder the corrosion process.
The standard gauge thicknesses would be 24-22-20-18-&-16 gauge. The stocking sheet sizes are usually either 4’Wide and either 8’L, 10’L, or 12’L, but larger widths of 5’ or 6’Wide is available.