NN3024 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the NN3024 model number is decoded

NN3024 is the standard section of the NTN NN3000 dimension series for a 120 mm shaft — 258 kN of basic dynamic capacity in a 3980 g, open bearing. The leading NN defines the rib arrangement (double row, ribbed inner ring, separable outer); the dimension-series digits and the two-digit bore code resolve to 120 mm, with 180 mm OD and 46 mm width from the ISO 15 general plan. The roller-set pitch sits inside the 30.0 mm radial section between the 120 mm bore and 180 mm OD; NTN prints Fw/Ew raceway diameters only for selected executions. Speed ratio check: limiting 3,300 r/min is .85 of the 3,900 r/min oil value for NN3024; grease-churn heating closes that gap as fill quantity rises. Heat the inner ring to max 120 °C for the 120 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 120 mm bore, oil-lubricated arrangements toward 3,900 r/min need positive flow and drain design; the 3980 g NN3024 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
• Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN3024 skids at 3,300 r/min and fails by smearing long before L10 fatigue.
• Wide (22/23) and light (10/49) executions at 120 mm bore share bore but not OD/width; check the full NN3000 series code before substituting, because housing and shoulder geometry will not interchange.
• Grease limiting speed 3,300 r/min and oil 3,900 r/min are different limits for NN3024: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
• The NN rib arrangement is not interchangeable with another prefix on the same 120 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 180×46 mm envelope matches.
• The 258/390 kN ratings, 42.5 kN Pu and 3980 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3024 (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.