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。
flat race surface style designator, 0.0374 inches minimum and 0.0413 inches maximum overall width, steel overall material, 52.00 millimeters nominal outside diameter, 35.00 millimeters nominal bore diameter