SKF® pre-lubricated sealed linear ball bearings can save time and money typically spent on the bearing lubrication process, which can be especially significant in high-volume applications. Available in both compact and standard metric versions, these linear ball bearings are fitted with integral double-lip seals to retain lubricant and protect against contamination. The seals consist of an inner lip that prevents lubricant from escaping within the bearing and an external lip that wipes the shaft surface as the bearing moves. The linear ball bearings also incorporate plastic cages to carry hardened steel raceway segments and guide the ball sets. The recirculating balls reduce friction and provide unlimited stroke to promote optimized performance. Shaft diameters range from 3 to 80 mm, and basic dynamic load ratings range from 60 N to 37,500 N, depending on size and type. Special greases for these pre-lubricated bearings can be selected to satisfy application-specific requirements. Available options include: raceway segments, balls manufactured from high-alloy stainless steel for corrosion resistance, all-stainless designs and custom designs for particular applications. (Pre-lubricated inch series bearings can be ordered.)