NUP348 bearing: complete specifications & equivalents
The NUP348 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 NUP348 |
| 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 & NUP300-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 NUP300-series | 20 mm |
| Largest outer diameter in NUP300-series | 580 mm |
| Width range across NUP300-series | 15–108 mm |
| Bore position in NUP300-series (smallest first) | 30 of 32 |
| Bore above smallest NUP300-series size | 220 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP348 | 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 NUP348 model number is decoded
NUP348 belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E: line-contact rollers between ground raceways for a 1590 kN dynamic rating in the 240 mm bore. Reading the code: NUP for the two-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 240 mm (00–03 use the 10/12/15/17 exception table). the bare number is the standard-capacity open execution with the normal pressed-steel cage; quote the full NUP348 designation when purchasing. Equivalent-load planning treats NUP348 as a pure radial bearing: keep P below 1590 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. On NUP 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
- 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
- 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
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- rolling-contact fatigue after the catalogue L10 life is exceeded
- hard-particle indentation of raceways in unfiltered oil or open arrangements
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 NUP348 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The NUP rib arrangement is not interchangeable with another prefix on the same 240 mm seat: inner ring two ribs + loose L-ring. Swapping NU for NJ changes axial location behaviour even though the 500×95 mm envelope matches.
- Grease limiting speed 1,300 r/min and oil 1,500 r/min are different limits for NUP348: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 130.0 mm section at 240 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 95 mm-wide cavity.
- The 95 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 240 mm inner ring.
- The 1590/1950 kN ratings, 160 kN Pu and 91300 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP348 (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 NUP348?
NUP348 is an NTN NUP 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. NUP348 is the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions.
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. NUP348 is supplied in the standard open execution shown in the table.
Can NUP348 take axial load and locate a shaft?
the NUP design provides two-direction axial location via its loose rib ring, for light/moderate thrust guidance. 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 NUP348?
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.