The article considers the issues of assuring the quality of the surfaces of machine parts by applying a preliminary local thermal impact before their edge cutting machining. In the zone of application of local thermal impact, a zone of metastable structure with respect to the material of the workpiece to be treated occurs. When the cutting plane intersects with the local thermal application line, the formed flow chip is segmented. The created graphs allow assigning of local thermal modes to the surface of the workpiece before edge cutting machining. Application of preliminary local thermal impact will assure the specified quality of the surface of the treated workpiece at semi-finishing and finishing edge cutting machining modes and stable segmentation of the flow chip.