NF348 bearing: complete specifications & equivalents
The NF348 is a ISO 15 radial bearing sized 240 x 500 x 95 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 240 mm |
| Outer diameter D | 500 mm |
| Width B | 95 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1590 kN |
| Basic static load rating C0 | 1950 kN |
| Fatigue load limit Pu | 160 kN |
| Limiting speed (mechanical) | 1300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 91300 g |
| Manufacturer designation | NTN NF348 |
| 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 | 9.449 in |
|---|---|
| Outer diameter D | 19.685 in |
| Width B | 3.74 in |
| ISO bore code | 48 |
| Radial section height (D−d)/2 | 130 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) | 30 of 32 |
| Bore above smallest NF300-series size | 220 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF348 | 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 NF348 model number is decoded
For pure radial duty on a 240 mm shaft NTN supplies NF348: one integral rib on each ring; the open execution is rated 1,300 r/min on grease and 1,500 r/min on oil. The leading NF defines the rib arrangement (one rib on each ring); the dimension-series digits and the two-digit bore code resolve to 240 mm, with 500 mm OD and 95 mm width from the ISO 15 general plan. NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of NF348. The 6.6 kN-per-mm-bore figure (1590 kN over 240 mm) lets a NF348 interchange candidate be screened quickly against the same-envelope ball or roller alternatives. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NF348.
Typical equipment & failure modes
Common applications
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- 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
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- At 240 mm bore, oil-lubricated arrangements toward 1,500 r/min need positive flow and drain design; the 91300 g NF348 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The NF rib arrangement is not interchangeable with another prefix on the same 240 mm seat: one rib on each ring. Swapping NU for NJ changes axial location behaviour even though the 500×95 mm envelope matches.
- If the shaft must be located both ways, do not use NF348 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Wide (22/23) and light (10/49) executions at 240 mm bore share bore but not OD/width; check the full NF300 series code before substituting, because housing and shoulder geometry will not interchange.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 500 mm race brinells and releases as vibration within hours.
- The 1590/1950 kN ratings, 160 kN Pu and 91300 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF348 (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 NF348?
NF348 is an NTN NF single-row cylindrical roller bearing to ISO 15: 240 mm bore, 500 mm OD and 95 mm width (9.449 × 19.685 × 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1590 kN, C0 1950 kN, Pu 160 kN, grease limiting speed 1,300 r/min, oil 1,500 r/min, mass about 91300 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. NF348 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. NF348 is supplied in the standard open execution shown in the table.
Can NF348 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 NF348?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 310 mm, Ew 430 mm. The nominal bore/OD remain 240/500 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,300 r/min grease / 1,500 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.