NF340 bearing: complete specifications & equivalents
The NF340 is a ISO 15 radial bearing sized 200 x 420 x 80 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 200 mm |
| Outer diameter D | 420 mm |
| Width B | 80 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1080 kN |
| Basic static load rating C0 | 1270 kN |
| Fatigue load limit Pu | 111 kN |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 54500 g |
| Manufacturer designation | NTN NF340 |
| 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 | 7.874 in |
|---|---|
| Outer diameter D | 16.535 in |
| Width B | 3.15 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 110 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) | 28 of 32 |
| Bore above smallest NF300-series size | 180 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF340 | 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 NF340 model number is decoded
NF340 is the standard section of the NTN NF300 dimension series for a 200 mm shaft — 1080 kN of basic dynamic capacity in a 54500 g, open bearing. On the NTN nameplate NF states which ring carries the ribs, which determines whether NF340 floats or locates; the numeric remainder is the ISO 15 series and 200 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. Selection arithmetic: Pu 111 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.18 (1270/1080 kN) shows the high-static-capacity proportioning of this 200 mm bore. Provide axial location with an adjacent locating bearing rather than expecting the float cylindrical set to hold thrust on the 200 mm shaft.
Typical equipment & failure modes
Common applications
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
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
- electrical pitting on VFD-driven motor shafts without grounding protection
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- At 200 mm bore, oil-lubricated arrangements toward 1,800 r/min need positive flow and drain design; the 54500 g NF340 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The 80 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 200 mm inner ring.
- Do not replace NF340 with a deep-groove ball bearing on rating alone: line contact gives 1080 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The 110.0 mm section at 200 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 80 mm-wide cavity.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 1080/1270 kN pair here belongs to NF340 as printed, not to the bare size.
- The 1080/1270 kN ratings, 111 kN Pu and 54500 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF340 (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 NF340?
NF340 is an NTN NF single-row cylindrical roller bearing to ISO 15: 200 mm bore, 420 mm OD and 80 mm width (7.874 × 16.535 × 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1080 kN, C0 1270 kN, Pu 111 kN, grease limiting speed 1,500 r/min, oil 1,800 r/min, mass about 54500 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. NF340 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. NF340 is supplied in the standard open execution shown in the table.
Can NF340 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 NF340?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 260 mm, Ew 360 mm. The nominal bore/OD remain 200/420 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,500 r/min grease / 1,800 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.