To investigate the accuracy of the sin square Psi method, in this paper, a four-point bending test is developed with which it is possible to load layers with defined tensile stresses. Then, the "effective surface E-modulus," which is calculated from the XRD measurements and the deflection, and the "volume E-modulus," which is calculated from the deflection and the applied load, are presented. High-density stainless steel is applied using HVOF, while the ceramic layers are produced using water-stabilized plasma spraying. The steel layers show a volume of elasticity that is twice as high as that of the surface elasticity module. No surface tension was observed in the ceramic layers during bending. This can be explained by the opening of crack structures as a result of tensile stress. In contrast to this, the pores can be expected to close under pressure loads and thus an increase in the stresses. Paper includes a German-language abstract.