A consideration in the design and development of any harvesting machine is to determine the physical and biomechanical properties of the tree and its fruit. Biomechanical properties such as tensile, bending and torsion strengths must be determined. In field experiments, the trees were selected from an orchard in Rafsanjan, Kerman Province, Iran. Parameters related to fruit properties were measured using load cells. In Rafsanjan’s Pistachio Research Institute laboratory, subsequent measurements were made using similar instrumentation. In a randomized design layout, 18 tree cultivars with 5 replications were selected. The maximum tensile, bending, and torsion strengths were found respectively for Badami Ravar, Momtaze Tajabadi and Italiaee cultivar clusters. Minimum tensile, bending, and torsional strengths were obtained for Ghazvini, Louk and Kalleh Ghoochi clusters. The cultivars Kalleh Ghoochi, Rezaee Zoodras and Khanjari Damghan were found to have fruit with the highest tensile, bending, and torsional strengths, with the lowest strengths characterizing the Italiaee cultivar.