N312EA bearing: complete specifications & equivalents
The N312EA is a ISO 15 radial bearing sized 60 x 130 x 31 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 60 mm |
| Outer diameter D | 130 mm |
| Width B | 31 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 177 kN |
| Basic static load rating C0 | 157 kN |
| Fatigue load limit Pu | 19.1 kN |
| Limiting speed (mechanical) | 4900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1770 g |
| Manufacturer designation | NTN N312EA |
| 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 | 2.362 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 1.22 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 35 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) | 10 of 33 |
| Bore above smallest N300-series size | 43 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N312EA | 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 N312EA model number is decoded
N312EA belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E, under the ＊ ULTAGE new-generation specification: line-contact rollers between ground raceways for a 177 kN dynamic rating in the 60 mm bore. Reading the code: N for the separable-outer-ring type, then the ISO 15 diameter/width series and the bore code — ×5 = 60 mm (00–03 use the 10/12/15/17 exception table). Minimum radial load matters: an unloaded N312EA at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Thermal planning around the 4,900 r/min grease ceiling should include the cage type (the EA high-capacity pressed sheet-steel cage) and oil-flow option to 7,000 r/min for continuously high-duty 60 mm positions. Provide axial location with an adjacent locating bearing rather than expecting the float cylindrical set to hold thrust on the 60 mm shaft.
Typical equipment & failure modes
Common applications
- large electric-motor and generator rotors
- cement and mining conveyor drive pulleys
- heavy industrial gearbox and reducer shafts
- large pump, turbine and compressor rotors
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- 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
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- Induction-heat the 60 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 130 mm raceway.
- The N rib arrangement is not interchangeable with another prefix on the same 60 mm seat: inner ring ribbed, outer ring ribless. Swapping NU for NJ changes axial location behaviour even though the 130×31 mm envelope matches.
- The N rib arrangement is not interchangeable with another prefix on the same 60 mm seat: inner ring ribbed, outer ring ribless. Swapping NU for NJ changes axial location behaviour even though the 130×31 mm envelope matches.
- The 35.0 mm section at 60 mm bore leaves a narrow oil path; with the EA pressed-steel-cage cage the relubrication groove and oil-level design must keep grease from churning in the 31 mm-wide cavity.
- Do not replace N312EA with a deep-groove ball bearing on rating alone: line contact gives 177 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 177/157 kN ratings, 19.1 kN Pu and 1770 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N312EA (EA pressed-steel-cage 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 N312EA?
N312EA is an NTN N single-row cylindrical roller bearing to ISO 15: 60 mm bore, 130 mm OD and 31 mm width (2.362 × 5.118 × 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 177 kN, C0 157 kN, Pu 19.1 kN, grease limiting speed 4,900 r/min, oil 7,000 r/min, mass about 1770 g. It is open, with the EA high-capacity 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. N312EA 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. This page's bearing carries the EA pressed-steel-cage execution.
Can N312EA 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 N312EA?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 77 mm, Ew 115 mm. The nominal bore/OD remain 60/130 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 4,900 r/min grease / 7,000 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.