NJ334 bearing: complete specifications & equivalents
The NJ334 is a ISO 15 radial bearing sized 170 x 360 x 72 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 | 360 mm |
| Width B | 72 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 885 kN |
| Basic static load rating C0 | 1010 kN |
| Fatigue load limit Pu | 92 kN |
| Limiting speed (mechanical) | 1800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 36100 g |
| Manufacturer designation | NTN NJ334 |
| 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 | 6.693 in |
|---|---|
| Outer diameter D | 14.173 in |
| Width B | 2.835 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 95 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) | 26 of 33 |
| Bore above smallest NJ300-series size | 153 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ334 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 NJ334 model number is decoded
NJ334 is the standard section of the NTN NJ300 dimension series for a 170 mm shaft — 885 kN of basic dynamic capacity in a 36100 g, open bearing. Digit by digit, NJ334 reads as NJ (inner ring two ribs + one outer rib), ISO 15 series, and bore 170 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. At 2,200 r/min with oil versus 1,800 r/min with grease (a 400 r/min band), lubrication choice for NJ334 is a thermal decision, not just a sealing one. Mass 36100 g for the 170×360×72 mm NJ334 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. On NJ 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
- 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
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- 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
- 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 170 mm bore, oil-lubricated arrangements toward 2,200 r/min need positive flow and drain design; the 36100 g NJ334 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The 95.0 mm section at 170 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 72 mm-wide cavity.
- Do not replace NJ334 with a deep-groove ball bearing on rating alone: line contact gives 885 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Grease limiting speed 1,800 r/min and oil 2,200 r/min are different limits for NJ334: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Grease limiting speed 1,800 r/min and oil 2,200 r/min are different limits for NJ334: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 885/1010 kN ratings, 92 kN Pu and 36100 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ334 (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 NJ334?
NJ334 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 170 mm bore, 360 mm OD and 72 mm width (6.693 × 14.173 × 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 885 kN, C0 1010 kN, Pu 92 kN, grease limiting speed 1,800 r/min, oil 2,200 r/min, mass about 36100 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. NJ334 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. NJ334 is supplied in the standard open execution shown in the table.
Can NJ334 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 NJ334?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 220 mm, Ew 310 mm. The nominal bore/OD remain 170/360 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,800 r/min grease / 2,200 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.