Slewing Bearings are Large-size rolling bearings which can accommodate axial, radial and moment loads either single or in combination direction. They can perform both movements oscillating as well as rotational. Basically a slewing bearing consists of inner ring, outer ring and rolling elements – balls or cylindrical rollers. The rolling elements are separated by polyamide spacers. The rings, which usually incorporates a gear are provided with holes to accommodate attachment bolts. The holes may be threaded. Generally, only the raceways in the rings are hardened and precision finish. Integral seals keeps the lubricant in, and contaminants out of the bearing. Slewing bearings are re-lubricated through grease fittings to reduce maintenance and operating costs.