NU248-MA bearing: complete specifications & equivalents
The NU248-MA 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 | SKF |
| 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 | brass |
| Basic dynamic load rating C | 952 kN |
| Basic static load rating C0 | 1370 kN |
| Fatigue load limit Pu | 129 kN |
| Reference speed (thermal) | 1600 rpm |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 51500 g |
| Manufacturer designation | SKF NU 248 MA |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.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) | 31 of 35 |
| Bore above smallest NU200-series size | 225 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ248-MA | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 240×440×72 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NUP248-MA | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 240×440×72 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
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-MA model number is decoded
In SKF catalogue PUB BU/P1 17000, SKF NU 248 MA denotes a single-row caged cylindrical roller bearing on the ISO 15 240×440×72 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 51500 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. Selection arithmetic: C0/C ≈ 1.44 (1370 against 952 kN), and the Pu figure 129 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 240 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- large rolling-mill drive trains
- marine propulsion line shafts
- heavy turbogenerator rotor supports
- mining hoist and winder shafts
Known failure patterns
- inner-ring raceway spalling from overload or contamination in the line-contact hertz zone
- outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating
- cage pocket wear from roller skew at light load
- cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up
- roller-end scoring from inadequate oil flow in the roller-raceway contact
- edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit
- brinelling from static overload or impact during handling and mounting
Selection pitfalls — read before you substitute
- Do not use a NU bearing where axial load must be carried — the design carries radial load only
- The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 248, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 248 MA and do not substitute rib styles without checking the shaft locating scheme.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 72 mm-wide ring and concentrates load.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- The 952/1370 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification.
Frequently asked questions
What are the dimensions and catalogue data of NU248-MA?
SKF NU 248 MA is a single-row caged cylindrical roller bearing with 240 mm bore, 440 mm OD and 72 mm width per ISO 15. SKF lists C 952 kN, C0 1370 kN, Pu 129 kN, reference speed 1,600 r/min and limiting speed 2,200 r/min, mass about 51500 g.
What does the NU designation and MA suffix mean?
The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable.
Can NU248-MA take axial load and locate the shaft?
No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty.
How does NU248-MA compare with the other executions in the same envelope?
The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number.
What limits the service life of this bearing most often?
Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.