Flexible screw conveyor features an innovative coupling design specific to the 3-A unit positioned beyond the point at which material exits the discharge spout, virtually eliminating the potential of contamination, while allowing quick disconnection of the screw from the motor drive for wash down. The only moving part contacting material is a flexible inner screw that self-centers as it rotates, providing clearance between itself and the tube wall and creating a gentle rolling action said to prevent the separation of blended materials. Numerous standard and custom-engineered screws are offered to move bulk materials ranging from large pellets to sub-micron powders, including products that pack, cake, smear, break-apart, seize or fluidize, with no separation of blended products. Mobile units are also available, as well as high-capacity models.