Helical Screw, worm or worm conveyor is one of the oldest and most versatile types of conveyors, designed to convey solid fluid materials and consists of a system of helical blades (helix rolled from a flat steel bar) or screw conveyor rotating inside a trough or stationary body. The material entering the trough or body is moved along its path by the rotation of the screw which is supported by supporting bearings. Inlets, outlets, gates and other accessories control the material and its disposition.

Screw conveyors are compact, easily adaptable to congested locations and can be mounted in horizontal, vertical or inclined configurations. Their brackets are simple and easily installed. They can be effectively sealed to prevent dust and fumes from escaping or to prevent moisture ingress.