Precision Tapered Roller Bearings。Idealfor heavy duty and power-towed casterapplications because their tapered faces will handle the most severe combination of downward and side forces。 Used in various Hamilton swivel assemblies as wellas in wheels。 　　Two bearings are installed per wheel， one ineach side of the hub， consisting of a cup（hardened and ground outer raceway） andcone （roller assembly）。 Tapered bearingsextend overall hub length of the wheel itselfby approximately w"。 　　Precision Ball Bearings。 Best suited whenrollability is important and side thrust is not acritical factor。 （Tapered bearings are bestsuited where side thrust is critical）。 Thebearings are pre-lubricated and sealed atthe factory so greasing is not required，reducing maintenance costs。 Double-sealedprecision ball bearings （shown on left） incor-porate steel reinforced rubber seals securelyfastened to a groove on the ring of bothsides of the bearing。 They now replacestraight roller bearings in the majority of ourcasters using polyurethane tread and solidurethane wheels and can be providedoptionally on many other wheel types。