In addition to geometry optimisation and the use of lightweight materials such as aluminium, a suitable service life calculation model is essential in the lightweight design process. For the realization of complex component geometries, mainly casting, especially sand casting, is used as a manufacturing technology. As an accompanying effect of this manufacturing process, detrimental fatigue-effective microstructural features occur both in the volume and in the surface layer of such components. Service life stresses are rarely comparable with those used in Wöhler tests under constant amplitude. Sequence effects caused by variable load amplitudes result in significantly different fatigue strength values. Service life based design offers potential for improvement in terms of cost and weight savings. In order to investigate this load time series based effect, fatigue tests will be performed under pulsating tensile load with both variable (VAL) and constant load amplitude (CAL). Simplified, block program tests are applied in the VAL test methodology. At first, the design of an existing linear tribometer is revised. By means of simulations and modal analyses the optimal solution concept is developed. Flat specimens with a casting rough surface are investigated. In detail, samples with two different heat treatment states (HIP and T6) are studied to evaluate pore effects. Next, a suitable test methodology is developed, whereby the drive control is realized by hardware and software packages from Siemens. Before testing, the 3D surface data is measured by a digital light microscope for subsequent evaluation. The cyclic fatigue tests are accompanied by fracture surface analyses. In both load cases (CAL and VAL), truncated pores as well as geometric surface notches are identified as crack initiation sites. By calculating the equivalence stress and the damage sum, fatigue strength is compared to recent literature. The comparison of service strength of fatigue life leads to a spectrum shape factor SSF = 0,92. In addition, non-propagating cracks could be detected on samples in the long-term test range which have been evaluated to assess crack arrest. In summary, the test results under block loading lead to a conservative life prediction in comparison to the numerical service strength assessment evaluation model.