The performance characteristics of screw augers were investigated as a function of auger dimensions, screw rotational speed and conveying inclination. The performance characteristics were studied in terms of the augers output, volumetric efficiency and power requirements. Three screw augers with diameters of 15.5, 20 and 25 cm were evaluated at four conveying angles of 0° (horizontal), 10, 20 and 30° and five rotational speeds of 200, 300, 400, 500 and 600 r.p.m. The experiments were conducted to a factorial statistical design. The results revealed that with increasing the screw rotational speed, the augers volumetric output increased and reached to a maximum point and after the point, the output started to be decreased. The volumetric output of the augers increased significantly (P<0.01) with increasing the auger dimensions. As the conveying inclination of the screw augers increased, the volumetric output and efficiency decreased, significantly (P<0.01). The power requirements of the augers increased with increasing the screw rotational speed and conveying inclination (P<0.01), while the value found to be deceased with increasing the auger dimensions (P<0.01). Comparing the results obtained in this study with the results had been previously reported for other cereal grains, it was concluded that the performance characteristics of screw augers can be affected by the properties of materials being conveyed.