Precision hard milling AISI H13 steel and AISI 52100 steel finds wide applications in mold and die industries. Surface integrity of machined surfaces is critical to component performance of fatigue and tribology. It has shown that micro cutting edge geometry has dominant effects on process efficiency and surface integrity. Therefore, a basic understanding of the cutting edge/workpiece interactions is critical for design of a cutting process for optimal product performance. Many experiments have been performed to understand the cutting edge/workpiece interactions by revealing the unique cutting mechanics and surface integrity due to the size effect of micro cutting edge. However, the cutting edge/workpeice contact zone is too small to study using cutting experiments. In this study the cutting edge/workpiece contact has been modeled with different cutting tool geometry. A 3D finite element simulation of cutting edge/workpiece was performed to study the material flow and frictional behaviors around the cutting edge in hard milling H13 steel. 2D finite element models have been developed to predict the cutting temperature penetration in the subsurface and the white layer thickness in hard machining AISI H13 and 52100 steel. The simulations results have been reasonably correlated with the experimental data.