NF305EA bearing: complete specifications & equivalents
The NF305EA is a ISO 15 radial bearing sized 25 x 62 x 17 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 25 mm |
| Outer diameter D | 62 mm |
| Width B | 17 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 49 kN |
| Basic static load rating C0 | 37.5 kN |
| Fatigue load limit Pu | 4.55 kN |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 242 g |
| Manufacturer designation | NTN NF305EA |
| 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 | 0.984 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 0.669 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 18.5 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) | 2 of 32 |
| Bore above smallest NF300-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF305EA | 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 NF305EA model number is decoded
NF305EA 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 49 kN dynamic rating in the 25 mm bore. Reading the code: NF for the rib-on-each-ring type, then the ISO 15 diameter/width series and the bore code — ×5 = 25 mm (00–03 use the 10/12/15/17 exception table). EA marks the high-capacity design: optimised roller complement in a pressed (stamped) sheet-steel cage for more load capacity than the basic number in the same ISO 15 envelope; the ＊ symbol printed before the number in 2203E marks the ULTAGE new-generation specification — upgraded material/geometry and longer rating life, not part of the order code; quote the full NF305EA designation when purchasing. Selection arithmetic: Pu 4.55 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 0.77 (37.5/49 kN) shows the high-static-capacity proportioning of this 25 mm bore. On NF arrangements confirm which ring is separable before heating: forcing the ribbed ring off over the roller complement damages the cage and rib faces.
Typical equipment & failure modes
Common applications
- two-wheeler and small-engine transmission shafts
- small pump and compressor rotor shafts
- appliance and office-machine drives
- agricultural PTO and implement gear shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- Small 25 mm-bore cylindrical rollers are skid-sensitive: ensure the radial load exceeds the minimum-load floor at operating speed, or the NF305EA rollers smear even with correct grease.
- Open NF305EA 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 25 mm contact.
- Wide (22/23) and light (10/49) executions at 25 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 17 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 25 mm inner ring.
- The 17 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 25 mm inner ring.
- The 49/37.5 kN ratings, 4.55 kN Pu and 242 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF305EA (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 NF305EA?
NF305EA is an NTN NF single-row cylindrical roller bearing to ISO 15: 25 mm bore, 62 mm OD and 17 mm width (0.984 × 2.441 × 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49 kN, C0 37.5 kN, Pu 4.55 kN, grease limiting speed 11,000 r/min, oil 15,600 r/min, mass about 242 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. NF305EA 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 NF305EA 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 NF305EA?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 34 mm, Ew 54 mm. The nominal bore/OD remain 25/62 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 11,000 r/min grease / 15,600 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.