The fuzzy logic approach was used for the modelling of hardness of beta-Sn single crystals alloys having different growth directions. The model was setup according to experimental results. The growth direction and load were assigned as inputs while microhardness was designed as output. It was aimed first to enrich the data and then to determine the best amounts of growth directions and loads that make the hardness of beta-Sn single crystals maximum by using modern optimisation techniques.