The mechanical properties of ductile irons (DI), as of most metallic materials, are measured and reported on standard machined specimens (as per ASTM). However, economic considerations dictate that castings be produced with a minimum of machining. Therefore, many castings retain most of the as-cast surface. This surface layer, commonly referred to as the casting skin, includes both surface and subsurface, and is typically incorporated in the term surface quality. Because of the casting skin, the mechanical properties of the part may be significantly different from those found on standard ASTM machined specimens. As the thickness of the casting decreases, the relative effect of the skin on the mechanical properties increases. This issue has received only limited attention. The project being conducted builds upon past work to further investigate the impact of process variables on the casting skin and the mechanical properties of light weight DI castings.