Surface hardening heat treatments have been shown to significantly improve strength, mitigate wear, and enhance the fatigue performance of wrought, cast, and sintered ferrous components [1]. As a result, surface hardened components are often placed in challenging applications that demand additional scrutiny to confirm specific design requirements such as surface hardness, case depth, and case microstructure. Case depth is of particular interest to the product designer because it characterizes the gradient in material properties near the surface, where stresses tend to be the highest.