C1018 is a general purpose low carbon steel with good case hardening qualities. It has a higher manganese content than certain other low carbon grades, such as 1020. With higher manganese, 1018 is better steel for carburized parts, since it produces a harder and more uniform case. It also has higher mechanical properties and better machinability due to the cold drawing process. Most 1018 is produced by cold drawing. In this process, oversize hot rolled bars, which have been cleaned of scale, are drawn through dies to the required size. Cold drawing increases tensile and yield strength but decreases ductility. Cold drawing also increases torsional strength, surface hardness and wear resistance. Due to size limitations of the cold drawing process, large diameter bars are generally turned and polished, the hot roll rounds usually machine turned, rather than drawn, then abrasively polished. C1018, available in rounds, flats, squares and hexagons, has a relatively large size selection.