ASTM.org publishes a complete list of steel grades. This site breaks down grades of steel by designated use such as metal fencing, carbon tubular steel, machinery and security barriers and fences. Within each use category, the website lists a series of steel and alloy metals.
Manufacturers designate grades of steel using an alphanumeric series that indicates the steel's rating, alloy composition and strength. The complete list at ASTM.org includes a brief description of the standard use and designation. Each individual steel grade includes a link to more detailed information about the uses and specifications of that particular alloy and designation.