This report summarizes the mechanical and physical properties of Hanford K Basin sludge constituents and includes the results of hardness measurements performed on irradiated uranium metal fuel. Understanding the characteristics and behavior of the sludge constituents is important for selecting appropriate surrogate materials for use in testing pumps and associated equipment that will be used for transferring and handling the sludge as a slurry for treatment and disposal. The inorganic components of the sludge include irradiated uranium metal and its radioactive corrosion products, such as uranium dioxide (UO 2 ), as well as non-radioactive materials. The mechanical properties of the irradiated uranium and its oxides are especially important, because they are very high density, hard materials with potentially jagged, sharp particle geometry that could be a challenge to slurry handling equipment.