The main aim of the present study is to develop, fabricate and evaluate a rotating grader for grading cereal corps. The effect of different orifice sizes (<7.5, 7.5 to 9.5 and 9.5 to 11.0 mm), inclination angles (0, 3, 5 and 7ᵒ) and rotational speeds of drum (25, 30, 35, 40, 45 and 50 rpm) were studied. The grader productivity, efficiency, specific energy consumption and costs were determined. The obtained results indicated that the grader productivity increased from 11.73 to 49.38, 145.72 to 213.38 and 110.29 to 236.52 kg h-1, with increasing orifices size from small to large, inclination angles increased from 0 to 7ᵒ and rotational speed of drum increased from 25 to 50 rpm, respectively. The grader efficiency decreased from 99.00 to 81.89, 89.38 to 87.12 and 89.46 to 86.62 %, with increasing orifices size from small to large, inclination angles increased from 0 to 7ᵒ and rotational speed of drum increased from 25 to 50 rpm, respectively. The specific energy consumption of grader increased from 10.77 to 13.62 and 9.14 to 14.81 kW h ton-1, with increasing inclination angles increased from 0 to 7ᵒ and rotational speed of drum increased from 25 to 50 rpm, respectively. The total cost of grader decreased from 0.07 to 0.05 and 0.09 to 0.04 EGP kg-1, with increasing inclination angles increased from 0 to 7ᵒ and rotational speed of drum increased from 25 to 50 rpm, respectively.