NJ340 bearing: complete specifications & equivalents
The NJ340 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 NJ340 |
| 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 & NJ300-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 NJ300-series | 17 mm |
| Largest outer diameter in NJ300-series | 580 mm |
| Width range across NJ300-series | 14–108 mm |
| Bore position in NJ300-series (smallest first) | 29 of 33 |
| Bore above smallest NJ300-series size | 183 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ340-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 200×420×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 NJ340 model number is decoded
NTN lists NJ340 on the 200×420 mm envelope, 80 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 1,500 r/min. Reading the code: NJ for the one-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 200 mm (00–03 use the 10/12/15/17 exception table). 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. Mass 54500 g for the 200×420×80 mm NJ340 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. 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 NJ340.
Typical equipment & failure modes
Common applications
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- fretting corrosion on a loose rotating shaft seat
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 NJ340 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- 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 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.
- The NJ rib arrangement is not interchangeable with another prefix on the same 200 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 420×80 mm envelope matches.
- 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 NJ340 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 NJ340 (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 NJ340?
NJ340 is an NTN NJ 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. NJ340 is two integral ribs on the inner ring and one rib on the outer ring — it locates the shaft in one axial direction.
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. NJ340 is supplied in the standard open execution shown in the table.
Can NJ340 take axial load and locate a shaft?
the NJ design accepts axial load in one direction and provides one-way shaft location. For two-direction location use an NUP execution or an NJ pair with loose rib rings.
What do Fw and Ew mean for NJ340?
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.