NF314 bearing: complete specifications & equivalents
The NF314 is a ISO 15 radial bearing sized 70 x 150 x 35 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 70 mm |
| Outer diameter D | 150 mm |
| Width B | 35 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 175 kN |
| Basic static load rating C0 | 168 kN |
| Fatigue load limit Pu | 20 kN |
| Limiting speed (mechanical) | 4700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2650 g |
| Manufacturer designation | NTN NF314 |
| 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 | 2.756 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.378 in |
| ISO bore code | 14 |
| Radial section height (D−d)/2 | 40 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) | 11 of 32 |
| Bore above smallest NF300-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF314 | 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 NF314 model number is decoded
The NTN order number NF314 denotes a 70×150×35 mm (2.756 × 5.906 × 1.378 in) cylindrical roller bearing in the NF300 family, a pressed sheet-steel cage. The leading NF defines the rib arrangement (one rib on each ring); the dimension-series digits and the two-digit bore code resolve to 70 mm, with 150 mm OD and 35 mm width from the ISO 15 general plan. The 40.0 mm radial section ((150−70)/2) frames the roller complement; capacity per millimetre of bore is about 2.5 kN/mm before application factors. Rating life at 175 kN C assumes clean oil and adequate film; the 20 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. Provide axial location with an adjacent locating bearing rather than expecting the float cylindrical set to hold thrust on the 70 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 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
- brinelling from static overload or impact during handling
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- Induction-heat the 70 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 150 mm raceway.
- Do not replace NF314 with a deep-groove ball bearing on rating alone: line contact gives 175 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 NF rib arrangement is not interchangeable with another prefix on the same 70 mm seat: one rib on each ring. Swapping NU for NJ changes axial location behaviour even though the 150×35 mm envelope matches.
- The 35 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 70 mm inner ring.
- The 40.0 mm section at 70 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 35 mm-wide cavity.
- The 175/168 kN ratings, 20 kN Pu and 2650 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF314 (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 NF314?
NF314 is an NTN NF single-row cylindrical roller bearing to ISO 15: 70 mm bore, 150 mm OD and 35 mm width (2.756 × 5.906 × 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 175 kN, C0 168 kN, Pu 20 kN, grease limiting speed 4,700 r/min, oil 5,500 r/min, mass about 2650 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. NF314 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. NF314 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can NF314 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 NF314?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 90 mm, Ew 130 mm. The nominal bore/OD remain 70/150 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 4,700 r/min grease / 5,500 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.