Abstract: A binder composition for use in making metal parts via a metal powder injection molding process containing the following components: (a) a first polymer with a relatively low solubility parameter such as polyethylene and polypropylene; (b) a second polymer with a relatively high solubility parameter such as polystyrene and poly(methyl methacrylate); and (c) a block copolymer containing blocks of the first and second, or other structurally similar, constituting monomeric units. Examples of the block copolymers include ethylene/styrene copolymer, propylene/styrene copolymer, and isoprene/styrene copolymer, etc. The binder composition is dispersed in an appropriate dispersant, such as an oil or wax, then blended with a metal powder to form a metal powder injection composition. The metal powder injection composition forms a green compact with a predetermined shape and dimension using an injection molding machine. Finally the green compact is sintered to form the final product.