Recent P/M development work has led to the introduction of two new families of alloys. These are the HFA (High Fatigue Alloy) series and SH (SinterHard) compositions. Property data, including Rolling Contact Fatigue data, has been developed for each of these. Advantages and disadvantages of each of the new products is discussed and comparisons are made with materials manufactured using the established “Mold/Sinter/Heat-Treat”, “UHD (Ultra-High Density” and WM (Warm Molding) technologies. Finally, specific gear applications is discussed with emphasis on why certain materials were selected for each.