in this research, an apparatus was made and utilized to determine the friction coeffi-cient of chickpea grains on steel surfaces. experiments were carried out on two black and galvanized surfaces and at four sliding velocities of 5, 20, 100 and 500 mm/min, at three moisture content of 7.5%, 15% and 21% wet basis (w.b.) and at three vertical pressure values of 14.28, 100 and 150 kpa. the followi...