NF312EA bearing: complete specifications & equivalents
The NF312EA 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 NF312EA |
| 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 & NF300-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 NF300-series | 20 mm |
| Largest outer diameter in NF300-series | 580 mm |
| Width range across NF300-series | 15–108 mm |
| Bore position in NF300-series (smallest first) | 9 of 32 |
| Bore above smallest NF300-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF312EA | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NF312EA model number is decoded
The NTN order number NF312EA denotes a 60×130×31 mm (2.362 × 5.118 × 1.22 in) cylindrical roller bearing in the NF300 family, the EA high-capacity pressed sheet-steel cage. On the NTN nameplate NF states which ring carries the ribs, which determines whether NF312EA floats or locates; the numeric remainder is the ISO 15 series and 60 mm bore reference, not a fit or clearance instruction. NTN prints the raceway diameters for this size — Fw 77 mm and Ew 115 mm — the envelope inside the 60/130 mm bore/OD where the rollers actually run. 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 NF arrangements. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NF312EA non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- heavy industrial gearbox and reducer shafts
- large pump, turbine and compressor rotors
- rolling-mill auxiliary drive shafts
- crusher and vibrating-screen drive shafts
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
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- false brinelling on standby machines exposed to external vibration
- false brinelling on standby machines exposed to external vibration
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 EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 177/157 kN pair here belongs to NF312EA as printed, not to the bare size.
- 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.
- 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.
- The NF rib arrangement is not interchangeable with another prefix on the same 60 mm seat: one rib on each ring. Swapping NU for NJ changes axial location behaviour even though the 130×31 mm envelope matches.
- The 177/157 kN ratings, 19.1 kN Pu and 1770 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF312EA (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 NF312EA?
NF312EA is an NTN NF 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. NF312EA is one integral rib on each ring — separable inner ring with single-direction axial guidance and a defined shaft position.
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 NF312EA take axial load and locate a shaft?
the NF design gives one-direction axial guidance via its single outer-ring rib. The loose rib ring still only suits light/short-duration axial guidance; heavy thrust belongs to a dedicated thrust bearing.
What do Fw and Ew mean for NF312EA?
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.