ASTM F75, a cobalt-chrome alloy, is the most dominant material used for total biomedical joint replacements due to the combination of its wear properties, corrosion resistance and bio-compatibility. As a result ASTM F75 is the material of choice for DePuys next-generation family of knee implants. These implants are investment cast to a near net shape and then finished by grinding. As material is removed, residual stress (RS) is released, allowing the part to distort to a new equilibrium state. This unpredictable dimensional distortion is frequently observed and is a significant cause of scrap. It is therefore essential to determine RS magnitudes and distributions within these parts to achieve predictability in the manufacture of high tolerance implants. A number femoral castings, as detailed in the experimental plan are proposed for neutron diffraction RS determination.