NF312 bearing: complete specifications & equivalents
The NF312 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 |
| Basic dynamic load rating C | 137 kN |
| Basic static load rating C0 | 126 kN |
| Fatigue load limit Pu | 15.4 kN |
| Limiting speed (mechanical) | 5500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1760 g |
| Manufacturer designation | NTN NF312 |
| 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 | 12 |
| 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 |
|---|---|---|---|
| NF312 | 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 NF312 model number is decoded
NF312 is the standard section of the NTN NF300 dimension series for a 60 mm shaft — 137 kN of basic dynamic capacity in a 1760 g, open bearing. Numbering ties NF312 to its envelope: type code NF, series NF300, 60 mm bore; the 130×31 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. Line contact between rollers and raceways gives NF312 high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. The 2.3 kN-per-mm-bore figure (137 kN over 60 mm) lets a NF312 interchange candidate be screened quickly against the same-envelope ball or roller alternatives. Keep the open bearing wrapped until fitting: the line-contact raceways of the 60 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.
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
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- brinelling from static overload or impact during handling
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.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NF312 skids at 5,500 r/min and fails by smearing long before L10 fatigue.
- If the shaft must be located both ways, do not use NF312 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Open NF312 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 60 mm contact.
- Wide (22/23) and light (10/49) executions at 60 mm bore share bore but not OD/width; check the full NF300 series code before substituting, because housing and shoulder geometry will not interchange.
- The 137/126 kN ratings, 15.4 kN Pu and 1760 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF312 (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 NF312?
NF312 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 137 kN, C0 126 kN, Pu 15.4 kN, grease limiting speed 5,500 r/min, oil 6,500 r/min, mass about 1760 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. NF312 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. NF312 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can NF312 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 NF312?
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 113 mm. The nominal bore/OD remain 60/130 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 5,500 r/min grease / 6,500 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.