Flexible screw weigh batching system comprises 8 low profile, motor-driven screw conveyors fed by roof-mounted storage vessels, with each group of 4 conveyors feeding either of 2 gain-in-weight hoppers. Controller starts and stops each conveyor to weigh ingredients in sequence, stopping material flow once accurate batch weight has been gained. Enclosed, dust-free conveyors can handle products ranging from submicron powders to large pellets.