N317 bearing: complete specifications & equivalents
The N317 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 N317 |
| 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 & N300-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 N300-series | 17 mm |
| Largest outer diameter in N300-series | 580 mm |
| Width range across N300-series | 14–108 mm |
| Bore position in N300-series (smallest first) | 15 of 33 |
| Bore above smallest N300-series size | 68 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N317-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 N317 model number is decoded
The NTN order number N317 denotes a 85×180×41 mm (3.346 × 7.087 × 1.614 in) cylindrical roller bearing in the N300 family, a pressed sheet-steel cage. Reading the code: N for the separable-outer-ring type, then the ISO 15 diameter/width series and the bore code — ×5 = 85 mm (00–03 use the 10/12/15/17 exception table). The 41 mm width and 47.5 mm section put the N300 series in the standard section; wide 22/23 variants at the same bore change OD, width and heat generation and are not drop-in swaps. Thermal planning around the 3,900 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 4,600 r/min for continuously high-duty 85 mm positions. 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
- large pump, turbine and compressor rotors
- rolling-mill auxiliary drive shafts
- crusher and vibrating-screen drive shafts
- marine gearbox and deck-machinery shafts
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
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- electrical pitting on VFD-driven motor shafts without grounding protection
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.
- Do not replace N317 with a deep-groove ball bearing on rating alone: line contact gives 235 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 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.
- Wide (22/23) and light (10/49) executions at 85 mm bore share bore but not OD/width; check the full N300 series code before substituting, because housing and shoulder geometry will not interchange.
- Open N317 units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 85 mm contact.
- The 235/228 kN ratings, 25.6 kN Pu and 4440 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N317 (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 N317?
N317 is an NTN N 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. N317 is two integral ribs on the inner ring and a ribless separable outer ring — equivalent float behaviour with the separable ring on the housing side.
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. N317 is supplied in the standard open execution shown in the table.
Can N317 take axial load and locate a shaft?
the N design is non-locating like NU but floats with the separable outer ring in the housing. Provide axial location with an adjacent locating bearing (angular-contact, deep-groove or a paired NJ/NUP set).
What do Fw and Ew mean for N317?
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.