These NTN Bearings are currently made high tech bearings. The roller cage is Polymide rather than the machined brass cages of old.Polymer cages are made of polyamide 66 (PA66), or polyamide 46 (PA46). The good sliding properties of polymer cages produce little friction and, therefore, permit high speeds.Under poor lubrication conditions, these cages reduce the risk of seizure and secondary damage because they can operate for some time with limited lubrication.
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