The flexible screw conveyor has a helicoid screw that rotates inside a fixed tube. Screw conveyors typically range in diameter from 2½ to 8 inches, and can be used for horizontal transports of up to 80 feet, and inclines of up to 60 degrees. An 8 inch diameter screw conveyor can transport 1,800 cubic feet/hour at 360 RPM at a 45 degree angle.