NU248 bearing: complete specifications & equivalents
The NU248 is a ISO 15 radial bearing sized 240 x 440 x 72 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 | 440 mm |
| Width B | 72 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1040 kN |
| Basic static load rating C0 | 1340 kN |
| Fatigue load limit Pu | 113 kN |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 49200 g |
| Manufacturer designation | NTN NU248 |
| 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 & NU200-series range
| Bore d | 9.449 in |
|---|---|
| Outer diameter D | 17.323 in |
| Width B | 2.835 in |
| ISO bore code | 48 |
| Radial section height (D−d)/2 | 100 mm |
| Smallest bore in NU200-series | 15 mm |
| Largest outer diameter in NU200-series | 580 mm |
| Width range across NU200-series | 11–92 mm |
| Bore position in NU200-series (smallest first) | 32 of 36 |
| Bore above smallest NU200-series size | 225 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU248-MA | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
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 NU248 model number is decoded
NU248 is an NTN NU cylindrical roller bearing: two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially, inside the 240×440×72 mm ISO 15 envelope. Digit by digit, NU248 reads as NU (outer ring ribbed, inner 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. The separable ring comes off without removing the roller assembly from the other ring, which eases inspection and lets the non-locating arrangement accommodate thermal shaft growth — the NU design floats on both sides. Rating life at 1040 kN C assumes clean oil and adequate film; the 113 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NU248 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive 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
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- At 240 mm bore, oil-lubricated arrangements toward 1,700 r/min need positive flow and drain design; the 49200 g NU248 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Grease limiting speed 1,500 r/min and oil 1,700 r/min are different limits for NU248: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 100.0 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 72 mm-wide cavity.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 440 mm race brinells and releases as vibration within hours.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 1040/1340 kN pair here belongs to NU248 as printed, not to the bare size.
- The 1040/1340 kN ratings, 113 kN Pu and 49200 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU248 (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 NU248?
NU248 is an NTN NU single-row cylindrical roller bearing to ISO 15: 240 mm bore, 440 mm OD and 72 mm width (9.449 × 17.323 × 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1040 kN, C0 1340 kN, Pu 113 kN, grease limiting speed 1,500 r/min, oil 1,700 r/min, mass about 49200 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. NU248 is two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially.
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. NU248 is supplied in the standard open execution shown in the table.
Can NU248 take axial load and locate a shaft?
the NU design carries no axial load and floats axially on both sides. 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 NU248?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 295 mm, Ew 385 mm. The nominal bore/OD remain 240/440 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,500 r/min grease / 1,700 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.