一種通常呈圓形的剛性部件,用於容納軸承。它用於定位軸承,但不會包裹軸承或限制軸承的運動。
0.0600 inches minimum and 0.0630 inches maximum overall width, 1.0950 inches minimum and 1.1150 inches maximum outside diameter, steel overall material, 0.6270 inches minimum and 0.6370 inches maximum bore diameter, flat race surface style designator