Iron losses have a significant contribution to the overall losses of high power density electrical machines operating as variable speed drives. During production, mechanical stress is applied to the soft magnetic material resulting in local magnetic deterioration and hence rising iron losses. Dependent on the cutting technique, geometrical sizes of tooth and yoke width or external loads from housing and shaft, the resulting local iron losses increase significantly. Hence, standardized Epstein or single sheet measurements under ideal sinusoidal condition underestimate the resulting machine's iron losses as the geometrical specimen sizes are to large to quantify the manufacturing influences. This paper applies a semi-physical approach to test bench machine measurements. The approach is derived from the parameter identification of an iron loss formula in due consideration of the different frequency and flux density dependencies of the various iron loss components. Thereby, a calibration of the used iron loss formulation considering manufacturing influences is presented. This allows an a-priori assessment of realistic iron losses during the design stage.