31320圓錐滾子軸承，31320尺寸，31320七類軸承

單列圓錐滾子軸承：32000 系列     32004--- 32024 (32004,32005,32010,32015)
                             32200 系列     32204---32236(32204,32205,32206,32210)
                             32300 系列     32304---32325(32305,32306,32307,32320)
                             33200 系列     33205---33221(33206,33208,33210,33220)
                             33100 系列     33108---33115(33109,33110,33114,33115)
                             30300 系列     30303---30318(30304,30305,30310,30315)
                             30200 系列     30203---30228(30204,30205,30215,30220)