Hard turning and grinding are finishing processes for the manufacture of precision components such as bearings, gears, and cams. However, the effects of distinct surface integrity by hard turning vs. grinding on rolling contact life are poorly understood. Four representative surface types were prepared: as-turned, as-ground, turned and polished, and ground and polished. Surface integrity was characterized by surface topography, microstructure, and micro/nanohardness. Fatigue tests were performed with an acoustic emission sensor and the signal processing software. The amplitude of acoustic emission signal is the most stable and sensitive signal to fatigue failure. The turned surface may have a longer life (>84%) than the ground one with equivalent surface finish.