NF324 bearing: complete specifications & equivalents
The NF324 is a ISO 15 radial bearing sized 120 x 260 x 55 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 260 mm |
| Width B | 55 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 500 kN |
| Basic static load rating C0 | 510 kN |
| Fatigue load limit Pu | 51 kN |
| Limiting speed (mechanical) | 2700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12500 g |
| Manufacturer designation | NTN NF324 |
| 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 & NF300-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 2.165 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NF300-series | 20 mm |
| Largest outer diameter in NF300-series | 580 mm |
| Width range across NF300-series | 15–108 mm |
| Bore position in NF300-series (smallest first) | 20 of 32 |
| Bore above smallest NF300-series size | 100 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF324 | 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 NF324 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, NF324 appears as a 120 mm bore single-row cylindrical roller bearing (500 kN C / 510 kN C0) with a pressed sheet-steel cage, listed to the ISO 15 boundary plan. On the NTN nameplate NF states which ring carries the ribs, which determines whether NF324 floats or locates; the numeric remainder is the ISO 15 series and 120 mm bore reference, not a fit or clearance instruction. The separable ring comes off without removing the roller assembly from the other ring, which eases inspection and lets the non-locating arrangement accommodate thermal shaft growth. Thermal planning around the 2,700 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 3,200 r/min for continuously high-duty 120 mm positions. On NF arrangements confirm which ring is separable before heating: forcing the ribbed ring off over the roller complement damages the cage and rib faces.
Typical equipment & failure modes
Common applications
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- rolling-contact fatigue after the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- At 120 mm bore, oil-lubricated arrangements toward 3,200 r/min need positive flow and drain design; the 12500 g NF324 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- If the shaft must be located both ways, do not use NF324 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- If the shaft must be located both ways, do not use NF324 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Grease limiting speed 2,700 r/min and oil 3,200 r/min are different limits for NF324: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 500/510 kN pair here belongs to NF324 as printed, not to the bare size.
- The 500/510 kN ratings, 51 kN Pu and 12500 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF324 (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 NF324?
NF324 is an NTN NF single-row cylindrical roller bearing to ISO 15: 120 mm bore, 260 mm OD and 55 mm width (4.724 × 10.236 × 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 500 kN, C0 510 kN, Pu 51 kN, grease limiting speed 2,700 r/min, oil 3,200 r/min, mass about 12500 g. It is open, with a pressed sheet-steel cage.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
The prefix states the rib arrangement: NU has two outer-ring ribs and a ribless inner ring (float, no axial load); NJ adds ribs for one-direction location; NUP adds a loose L-ring to locate both directions; N has two inner-ring ribs and a separable outer ring; NF has one rib per ring for one-direction guidance. NF324 is one integral rib on each ring — separable inner ring with single-direction axial guidance and a defined shaft position.
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. NF324 is supplied in the standard open execution shown in the table.
Can NF324 take axial load and locate a shaft?
the NF design gives one-direction axial guidance via its single outer-ring rib. The loose rib ring still only suits light/short-duration axial guidance; heavy thrust belongs to a dedicated thrust bearing.
What do Fw and Ew mean for NF324?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 154 mm, Ew 226 mm. The nominal bore/OD remain 120/260 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,700 r/min grease / 3,200 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.