NU2268-MA bearing: complete specifications & equivalents
The NU2268-MA is a ISO 15 radial bearing sized 340 x 620 x 165 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 340 mm |
| Outer diameter D | 620 mm |
| Width B | 165 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 2640 kN |
| Basic static load rating C0 | 4500 kN |
| Fatigue load limit Pu | 365 kN |
| Reference speed (thermal) | 1000 rpm |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 226000 g |
| Manufacturer designation | SKF NU 2268 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 & NU2200-series range
| Bore d | 13.386 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 6.496 in |
| ISO bore code | 68 |
| Radial section height (D−d)/2 | 140 mm |
| Smallest bore in NU2200-series | 17 mm |
| Largest outer diameter in NU2200-series | 1030 mm |
| Width range across NU2200-series | 16–272 mm |
| Bore position in NU2200-series (smallest first) | 35 of 39 |
| Bore above smallest NU2200-series size | 323 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU2268-MA model number is decoded
SKF NU 2268 MA is a single-row caged cylindrical roller bearing sized 340×620×165 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means 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; functionally the bearing is 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. Load-per-bore for the 340 mm seat is about 7.76 kN/mm, typical of dimension series 22 (light-section, wide); use C0 4500 kN for static checks such as crane hook blocks standing under load. 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 340 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- offshore drawworks shafts
- large rolling-mill drive trains
- marine propulsion line shafts
- heavy turbogenerator rotor supports
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
- polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant
- surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load
- edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit
- electrical pitting on VFD-driven shafts without grounding protection
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 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2268, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2268 MA and do not substitute rib styles without checking the shaft locating scheme.
- Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 620 mm raceway.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- The 2640/4500 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 NU2268-MA?
SKF NU 2268 MA is a single-row caged cylindrical roller bearing with 340 mm bore, 620 mm OD and 165 mm width per ISO 15. SKF lists C 2640 kN, C0 4500 kN, Pu 365 kN, reference speed 1,000 r/min and limiting speed 1,500 r/min, mass about 226000 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 NU2268-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 NU2268-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.