Alloy steel consists of carbon steel plus additional elements that increase its strength, hardness, and wear resistance properties. Alloy steel sheets and plates are solid and flat pieces of metal that come in different sizes and material grades for fabricating metal parts and other items. Alloy steel bars, rods, and discs are available in different sizes and material grades and used for parts in machining, welding, and structural applications. Alloy steel round tubes are hollow, durable, and easy to form and weld. Alloy steel ball stock is commonly used as ball bearings for industrial motion applications.