... Thrust roller bearings: 1.GCr15, GCr15SiMn, G20Cr2Ni4A 2.Precision level:P0,P4,P5,P6 3.Vibration:Z1V1,Z2V2,Z3V3 1). Flat-race thrust bearings: Consist ... -race bearing and limiting speed is about three times as high. However, a thrust bearing has a limiting speed, which ... quite low because balls spin at high speeds. (3). Two-directional, grooved-race thrust bearings: It consist of two stationary races ...