Microstructural particle rotations have been reported to occur in the deformation processes. The characterization of particle rotation becomes important as it reflects surface deformation and material's surface integrity and subsequent material damage leading to component failure. Machining such as hard turning and grinding poses great challenges for material modeling as they involve large strain, high strain rate and temperatures. In this work, the particle rotation has been investigated for hard turning and grinding processes. This work compares the effects of hard turning and grinding processes on the second phase particle rotation in AISI 52100 steel. It is discovered that the microstructure evolves differently for different processes. Interestingly, these microstructure variations, apart from being a major function of load intensity, largely depend on the mode of deformation, also. Further, these effects have been studied as a function of severity of process conditions, mechanical loading, heat generation and work piece depth.