NJ317 bearing: complete specifications & equivalents
The NJ317 is a ISO 15 radial bearing sized 85 x 180 x 41 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 85 mm |
| Outer diameter D | 180 mm |
| Width B | 41 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 235 kN |
| Basic static load rating C0 | 228 kN |
| Fatigue load limit Pu | 25.6 kN |
| Limiting speed (mechanical) | 3900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 4440 g |
| Manufacturer designation | NTN NJ317 |
| 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 | 3.346 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 1.614 in |
| ISO bore code | 17 |
| Radial section height (D−d)/2 | 47.5 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) | 15 of 33 |
| Bore above smallest NJ300-series size | 68 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ317-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 85×180×41 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 NJ317 model number is decoded
NJ317 is an NTN NJ cylindrical roller bearing: two integral ribs on the inner ring and one rib on the outer ring — it locates the shaft in one axial direction, inside the 85×180×41 mm ISO 15 envelope. The leading NJ defines the rib arrangement (inner ring two ribs + one outer rib); the dimension-series digits and the two-digit bore code resolve to 85 mm, with 180 mm OD and 41 mm width from the ISO 15 general plan. NTN prints two speed ceilings: 3,900 r/min grease and 4,600 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 85 mm bore. The 2.8 kN-per-mm-bore figure (235 kN over 85 mm) lets a NJ317 interchange candidate be screened quickly against the same-envelope ball or roller alternatives. Heat the inner ring to max 120 °C for the 85 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
Typical equipment & failure modes
Common applications
- rolling-mill auxiliary drive shafts
- crusher and vibrating-screen drive shafts
- marine gearbox and deck-machinery shafts
- large electric-motor and generator rotors
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
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- rolling-contact fatigue after the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- Induction-heat the 85 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 180 mm raceway.
- The NJ rib arrangement is not interchangeable with another prefix on the same 85 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 180×41 mm envelope matches.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ317 skids at 3,900 r/min and fails by smearing long before L10 fatigue.
- The 47.5 mm section at 85 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 41 mm-wide cavity.
- If the shaft must be located both ways, do not use NJ317 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 235/228 kN ratings, 25.6 kN Pu and 4440 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ317 (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 NJ317?
NJ317 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 85 mm bore, 180 mm OD and 41 mm width (3.346 × 7.087 × 1.614 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 235 kN, C0 228 kN, Pu 25.6 kN, grease limiting speed 3,900 r/min, oil 4,600 r/min, mass about 4440 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. NJ317 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. NJ317 is supplied in the standard open execution shown in the table.
Can NJ317 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 NJ317?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 108 mm, Ew 156 mm. The nominal bore/OD remain 85/180 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 3,900 r/min grease / 4,600 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.