Transmission torque converter reactor thrust washer segments (12) comprising a surface hardenable aluminum alloy are subjected to electrical discharge machining (EDM) using an electrode (26) and under conditions effective to impart a hydrodynamic bearing surface profile to the segment surfaces (12a), reduce segment surface roughness, and increase segment surface hardness. Torque converter reactors (10) having integrated thrust washer segments machined in this manner exhibit improved wear resistance and hydrodynamic lift when compared to as cast thrust washer segments.