Alloy steel is a type of steel that is alloyed with a range of elements in total amounts between 1 % to 50 % in order to improve its mechanical properties. It is basically divided into two groups which are low alloy steel and high alloy steel . The difference between the two comes from the total percentage of alloying elements. If the percentage is below or equal to 4 %, then the steel would be referred as low alloy steel otherwise it comes in the category of high alloy steel. Common alloyants include carbon, manganese, nickel, molybdenum, chromium, vanadium, silicon and boron.