An assembly such as a piston assembly for an engine includes a piston pin that has an outer member and a core. The outer member has a cavity extending lengthwise therethrough. The cavity has a first volume. The core is fit to the outer member in the cavity, and has a second volume less than the first volume. For example, the second volume may be less than the first volume because the core has an opening, because the core is shorter in length than the cavity, or both. A method of manufacturing a piston pin includes providing an outer member having a first density and a first length, creating a cavity that extends lengthwise through the outer member, providing a core having a second density and a second length, and inserting the core into the cavity of the outer member.