N315 bearing: complete specifications & equivalents
The N315 is a ISO 15 radial bearing sized 75 x 160 x 37 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 160 mm |
| Width B | 37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 211 kN |
| Basic static load rating C0 | 205 kN |
| Fatigue load limit Pu | 23.8 kN |
| Limiting speed (mechanical) | 4400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3210 g |
| Manufacturer designation | NTN N315 |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.457 in |
| ISO bore code | 15 |
| Radial section height (D−d)/2 | 42.5 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) | 13 of 33 |
| Bore above smallest N300-series size | 58 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N315-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 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 N315 model number is decoded
N315 is the standard section of the NTN N300 dimension series for a 75 mm shaft — 211 kN of basic dynamic capacity in a 3210 g, open bearing. On the NTN nameplate N states which ring carries the ribs, which determines whether N315 floats or locates; the numeric remainder is the ISO 15 series and 75 mm bore reference, not a fit or clearance instruction. Minimum radial load matters: an unloaded N315 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. With the inner ring rotating, catalogue practice is a k5/m5 shaft seat and an H7/H6 housing; the outer ring must remain free to creep slightly axially in non-locating N arrangements. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a N315 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- marine gearbox and deck-machinery shafts
- large electric-motor and generator rotors
- cement and mining conveyor drive pulleys
- heavy industrial gearbox and reducer shafts
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
- fretting corrosion on a loose rotating shaft seat
- brinelling from static overload or impact during handling
Selection pitfalls — read before you substitute
- Induction-heat the 75 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 160 mm raceway.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N315 skids at 4,400 r/min and fails by smearing long before L10 fatigue.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N315 skids at 4,400 r/min and fails by smearing long before L10 fatigue.
- Grease limiting speed 4,400 r/min and oil 5,200 r/min are different limits for N315: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Do not replace N315 with a deep-groove ball bearing on rating alone: line contact gives 211 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 211/205 kN ratings, 23.8 kN Pu and 3210 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N315 (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 N315?
N315 is an NTN N single-row cylindrical roller bearing to ISO 15: 75 mm bore, 160 mm OD and 37 mm width (2.953 × 6.299 × 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 211 kN, C0 205 kN, Pu 23.8 kN, grease limiting speed 4,400 r/min, oil 5,200 r/min, mass about 3210 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. N315 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. N315 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can N315 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 N315?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 95.5 mm, Ew 139.5 mm. The nominal bore/OD remain 75/160 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 4,400 r/min grease / 5,200 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.