The present work is carried out on the design and modelling of IS-3 size actuator under industrial simulated conditions. The two different materials 50CrV4 and SUP9/SAE 5160 are tested for the load capacity of spring at different stroke length. On the other side, the second material selected was 50CrV4 and SUP 9/SAE 5160 with wire diameters of 28 mm and 30 mm and the same procedures were applied and both the results were compared with the standard data. Shear stress and deformation calculated using FEA solver at position 85 of precompression, 50 mm stroke after precompression and 100 mm full stroke after precompression. Finite element analysis was performed to predict the fatigue life behaviour of both springs based on SN curve and strain life parameters. 50CrV4 generally offers better fatigue resistance and less sensitivity to loading conditions compared to SUP9/SAE 5160. This makes 50CrV4 a more suitable choice for helical spring applications where fatigue loading is a critical factor. Obtained results for fatigue life based on mean stress curve methods which gives better predictions under the industrial simulated load conditions.