NF234 bearing: complete specifications & equivalents
The NF234 is a ISO 15 radial bearing sized 170 x 310 x 52 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 170 mm |
| Outer diameter D | 310 mm |
| Width B | 52 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 530 kN |
| Basic static load rating C0 | 635 kN |
| Fatigue load limit Pu | 59.5 kN |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 16700 g |
| Manufacturer designation | NTN NF234 |
| 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 & NF200-series range
| Bore d | 6.693 in |
|---|---|
| Outer diameter D | 12.205 in |
| Width B | 2.047 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NF200-series | 20 mm |
| Largest outer diameter in NF200-series | 580 mm |
| Width range across NF200-series | 14–92 mm |
| Bore position in NF200-series (smallest first) | 25 of 34 |
| Bore above smallest NF200-series size | 150 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF234 | 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 NF234 model number is decoded
NTN lists NF234 on the 170×310 mm envelope, 52 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 2,200 r/min. On the NTN nameplate NF states which ring carries the ribs, which determines whether NF234 floats or locates; the numeric remainder is the ISO 15 series and 170 mm bore reference, not a fit or clearance instruction. NTN prints the raceway diameters for this size — Fw 208 mm and Ew 272 mm — the envelope inside the 170/310 mm bore/OD where the rollers actually run. Thermal planning around the 2,200 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 2,500 r/min for continuously high-duty 170 mm positions. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NF234.
Typical equipment & failure modes
Common applications
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- rolling-contact fatigue after the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- At 170 mm bore, oil-lubricated arrangements toward 2,500 r/min need positive flow and drain design; the 16700 g NF234 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Do not replace NF234 with a deep-groove ball bearing on rating alone: line contact gives 530 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 310 mm race brinells and releases as vibration within hours.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 530/635 kN pair here belongs to NF234 as printed, not to the bare size.
- The NF rib arrangement is not interchangeable with another prefix on the same 170 mm seat: one rib on each ring. Swapping NU for NJ changes axial location behaviour even though the 310×52 mm envelope matches.
- The 530/635 kN ratings, 59.5 kN Pu and 16700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF234 (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 NF234?
NF234 is an NTN NF single-row cylindrical roller bearing to ISO 15: 170 mm bore, 310 mm OD and 52 mm width (6.693 × 12.205 × 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 530 kN, C0 635 kN, Pu 59.5 kN, grease limiting speed 2,200 r/min, oil 2,500 r/min, mass about 16700 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. NF234 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. NF234 is supplied in the standard open execution shown in the table.
Can NF234 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 NF234?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 208 mm, Ew 272 mm. The nominal bore/OD remain 170/310 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,200 r/min grease / 2,500 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.