NN4960 bearing: complete specifications & equivalents
The NN4960 is a ISO 15 radial bearing sized 300 x 420 x 118 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 300 mm |
| Outer diameter D | 420 mm |
| Width B | 118 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1330 kN |
| Basic static load rating C0 | 2800 kN |
| Fatigue load limit Pu | 231 kN |
| Limiting speed (mechanical) | 1300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 46400 g |
| Manufacturer designation | NTN NN4960 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
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.
Dimensions in inches & NN4900-series range
| Bore d | 11.811 in |
|---|---|
| Outer diameter D | 16.535 in |
| Width B | 4.646 in |
| ISO bore code | 60 |
| Radial section height (D−d)/2 | 60 mm |
| Smallest bore in NN4900-series | 100 mm |
| Largest outer diameter in NN4900-series | 440 mm |
| Width range across NN4900-series | 40–118 mm |
| Bore position in NN4900-series (smallest first) | 17 of 18 |
| Bore above smallest NN4900-series size | 200 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN4960 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NN4960 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, NN4960 appears as a 300 mm bore single-row cylindrical roller bearing (1330 kN C / 2800 kN C0) with a machined or stamped steel cage per the precision execution, listed to the ISO 15 boundary plan. On the NTN nameplate NN states which ring carries the ribs, which determines whether NN4960 floats or locates; the numeric remainder is the ISO 15 series and 300 mm bore reference, not a fit or clearance instruction. Double-row NN precision cylindrical roller bearing: ribbed inner ring with a separable outer ring, two roller rows for high radial stiffness on machine-tool spindles; precision classes P5/P4/P2 and clearance are ordered separately. Thermal planning around the 1,300 r/min grease ceiling should include the cage type (a machined or stamped steel cage per the precision execution) and oil-flow option to 1,500 r/min for continuously high-duty 300 mm positions. Provide axial location with an adjacent locating bearing rather than expecting the float cylindrical set to hold thrust on the 300 mm shaft.
Typical equipment & failure modes
Common applications
- coordinate-measuring and semiconductor-equipment drives
- machine-tool main spindles requiring high radial stiffness
- precision gearbox and indexing-drive shafts
- high-rpm motorised grinding and milling spindles
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- At 300 mm bore, oil-lubricated arrangements toward 1,500 r/min need positive flow and drain design; the 46400 g NN4960 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Double-row NN precision bearings are typically ordered P5/P4 with specific radial clearance for spindle preloading; a P0/CN NN4960 does not substitute a precision-class execution.
- The 118 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 300 mm inner ring.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN4960 skids at 1,300 r/min and fails by smearing long before L10 fatigue.
- The 118 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 300 mm inner ring.
- The 1330/2800 kN ratings, 231 kN Pu and 46400 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN4960 (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.
Frequently asked questions
What are the dimensions and catalogue data of NN4960?
NN4960 is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 300 mm bore, 420 mm OD and 118 mm width (11.811 × 16.535 × 4.646 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1330 kN, C0 2800 kN, Pu 231 kN, grease limiting speed 1,300 r/min, oil 1,500 r/min, mass about 46400 g. It is open, with a machined or stamped steel cage per the precision execution.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
NN and NNU are double-row precision designs rather than single-row rib variants: NN has a ribbed inner ring and separable outer ring, NNU the reverse; both give high radial stiffness for spindles and are commonly ordered with P5/P4 precision and a K 1:12 tapered bore for preload setting. NN4960 is the NN execution.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NN4960 is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN4960?
NN4960 has a cylindrical bore and mounts on a plain machined shaft seat; a K execution (1:12 taper) exists in the NN4900 series when preload must be set by drive-up on a tapered seat.
What do Fw and Ew mean for NN4960?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 339 mm. The nominal bore/OD remain 300/420 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,300 r/min grease / 1,500 r/min oil.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.