21311EXW33K Nachi Spherical Roller Bearing Steel Cage : Tapered Bore Made in Japan 21311EXW33K Nachi Spherical Roller Bearing, Steel Cage, the bearing has a tapered inner ring bore (K), Made in Japan, the 21311EXW33K inner diameter is 55mm, the 21311EXW33K outer diameter is 120mm and the 21311EXW33K width is 29mm.