Linear motion products are used in conveyors and assembly operations to provide movement in a straight line, including rolling elements in a raceway or guide rail. They also keep parts and machinery moving and aligned. Movement can be forward or backward and either vertical or horizontal. Actuators, ball screws, and nuts convert rotating movement, such as that coming from a motor, to movement in a straight line. Bearing guides, guide rails, shafts, and carriages (slides) align components to reduce friction and provide smooth, precise movement. Magnetic capping headsets apply caps to small bottles. Sleeve bearings, and mounted and unmounted linear bearings, reduce wear caused by friction and evenly distribute loads for use with heavy loads. Screws are used with screw jacks, presses, and linear actuators at low-to-moderate speeds under heavy loads.