Steels containing alloying elements and with qualities superior to those of carbon steels. An alloy steel is defined as meeting one or more of the following conditions: having a manganese content greater than 1.65%, a silicon content greater than 0.5%, a copper content greater than 0.6%, or specified minimum quantities of chromium, molybdenum, nickel, tungsten, or vanadium. Alloys with a total of less than 5% of such elements are considered low alloy steels. Alloys with more than 11% chromium are generally considered stainless steels. Most alloy steel is medium- or high-carbon steel.