NUH2248-ECMH-PEX bearing: complete specifications & equivalents
The NUH2248-ECMH-PEX is a ISO 15 radial bearing sized 240 x 440 x 120 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 | 120 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 2279 kN |
| Basic static load rating C0 | 3050 kN |
| Fatigue load limit Pu | 275 kN |
| Reference speed (thermal) | 1600 rpm |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 80000 g |
| Manufacturer designation | SKF NUH 2248 ECMH/PEX |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity 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. 6.2 high-capacity 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 & NUH2200-series range
| Bore d | 9.449 in |
|---|---|
| Outer diameter D | 17.323 in |
| Width B | 4.724 in |
| ISO bore code | 48 |
| Radial section height (D−d)/2 | 100 mm |
| Smallest bore in NUH2200-series | 100 mm |
| Largest outer diameter in NUH2200-series | 440 mm |
| Width range across NUH2200-series | 46–120 mm |
| Bore position in NUH2200-series (smallest first) | 13 of 13 |
| Bore above smallest NUH2200-series size | 140 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUH2248-ECMH | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same ISO 15 envelope 240×440×120 mm, but catalogue C/C0 ratings differ between executions (2279/3050 vs 1980/3050 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent. |
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 NUH2248-ECMH-PEX model number is decoded
NUH2248-ECMH-PEX is the 240 mm bore entry in the NUH2200 range: a 240×440×120 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 2279 kN / C0 3050 kN. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.34 (3050 against 2279 kN), and the Pu figure 275 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 1,700 r/min mechanical limiting speed. Fit practice for NUH2248-ECMH-PEX: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 2279 kN / C0 3050 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2248-ECMH-PEX as a separate service part: do not substitute the standard NUH 2248 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.
Typical equipment & failure modes
Common applications
- large mining mill pinion shafts
- multi-megawatt wind turbine main gearboxes
- offshore and marine heavy drive trains
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
- micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment
- cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up
- surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load
- cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded
- smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load
Selection pitfalls — read before you substitute
- High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.
- The /PEX pinion build and the standard NUH 2248 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 120 mm-wide ring and concentrates load.
- Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 440 mm raceway.
- The 2279/3050 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX 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 NUH2248-ECMH-PEX?
SKF NUH 2248 ECMH/PEX is a high-capacity cylindrical roller bearing with 240 mm bore, 440 mm OD and 120 mm width per ISO 15. SKF lists C 2279 kN, C0 3050 kN, Pu 275 kN, reference speed 1,600 r/min and limiting speed 1,700 r/min, mass about 80000 g.
What does the NUH designation and ECMH/PEX suffix mean?
The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring.
Can NUH2248-ECMH-PEX take axial load and locate the shaft?
In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing.
How does NUH2248-ECMH-PEX 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. 6.2 high-capacity cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.