Disclosed is an improved screw conveyor that reduces maintenance. The screw conveyor comprises an elongate trough assembly comprising material input and output gates formed thereon and an elongate screw fighting rotably disposed within the trough assembly. The fighting comprises an elongate hollow shaft comprising a plurality of thorough fluid holes disposed thereon, a proximal end of the shaft adapted to receive a fluid therethrough whereby, the received fluid is discharged from the plurality of fluid holes, and a pair of parallel blades helically wound around the shaft, the blades arranged such that, the fluid holes are disposed between the blades. The fluid is discharged from between the blades forms a pressurized shield between the outer edges of blades and the inner surface of the trough assembly so as to prevent the material from entering the space between the edges of the blades and the inner surface of the trough assembly.