N348 bearing: complete specifications & equivalents
The N348 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 N348 |
| 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 & N300-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 N300-series | 17 mm |
| Largest outer diameter in N300-series | 580 mm |
| Width range across N300-series | 14–108 mm |
| Bore position in N300-series (smallest first) | 31 of 33 |
| Bore above smallest N300-series size | 223 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N348 | 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 N348 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, N348 appears as a 240 mm bore single-row cylindrical roller bearing (1590 kN C / 1950 kN C0) with a pressed sheet-steel cage, listed to the ISO 15 boundary plan. Digit by digit, N348 reads as N (inner ring ribbed, outer ring ribless), ISO 15 series, and bore 240 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. NTN prints two speed ceilings: 1,300 r/min grease and 1,500 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 240 mm bore. Selection arithmetic: Pu 160 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.23 (1950/1590 kN) shows the high-static-capacity proportioning of this 240 mm bore. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a N348 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- brinelling from static overload or impact during handling
- brinelling from static overload or impact during handling
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 N348 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Grease limiting speed 1,300 r/min and oil 1,500 r/min are different limits for N348: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Grease limiting speed 1,300 r/min and oil 1,500 r/min are different limits for N348: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Grease limiting speed 1,300 r/min and oil 1,500 r/min are different limits for N348: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- If the shaft must be located both ways, do not use N348 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 1590/1950 kN ratings, 160 kN Pu and 91300 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N348 (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 N348?
N348 is an NTN N 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. N348 is two integral ribs on the inner ring and a ribless separable outer ring — equivalent float behaviour with the separable ring on the housing side.
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. N348 is supplied in the standard open execution shown in the table.
Can N348 take axial load and locate a shaft?
the N design is non-locating like NU but floats with the separable outer ring in the housing. Provide axial location with an adjacent locating bearing (angular-contact, deep-groove or a paired NJ/NUP set).
What do Fw and Ew mean for N348?
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.