NU1964-ECMA bearing: complete specifications & equivalents
The NU1964-ECMA is a ISO 15 radial bearing sized 320 x 440 x 56 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 320 mm |
| Outer diameter D | 440 mm |
| Width B | 56 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 693 kN |
| Basic static load rating C0 | 1200 kN |
| Fatigue load limit Pu | 110 kN |
| Reference speed (thermal) | 1500 rpm |
| Limiting speed (mechanical) | 2000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 26000 g |
| Manufacturer designation | SKF NU 1964 ECMA |
| 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 & NU1900-series range
| Bore d | 12.598 in |
|---|---|
| Outer diameter D | 17.323 in |
| Width B | 2.205 in |
| ISO bore code | 64 |
| Radial section height (D−d)/2 | 60 mm |
| Smallest bore in NU1900-series | 320 mm |
| Largest outer diameter in NU1900-series | 850 mm |
| Width range across NU1900-series | 56–100 mm |
| Bore position in NU1900-series (smallest first) | 1 of 6 |
| Bore above smallest NU1900-series size | 0 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU1964-ECMA model number is decoded
For a 320 mm shaft, SKF lists NU1964-ECMA as single-row caged cylindrical roller: 440 mm OD, 56 mm wide, Pu 110 kN, the catalogue lists 1,500 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. 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 ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 693 kN and C0 1200 kN, size the bearing on the 320×440 mm ISO 15 envelope and check the 110 kN Pu against the equivalent-load floor; the catalogue lists 1,500 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Fit practice for NU1964-ECMA: 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. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.
Typical equipment & failure modes
Common applications
- heavy turbogenerator rotor supports
- mining hoist and winder shafts
- offshore drawworks shafts
- large rolling-mill 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
- 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
- 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
- false brinelling on standby machines exposed to external vibration
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 19 (ultra-slim section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 1964, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 1964 ECMA 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 56 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 693/1200 kN ratings are SKF catalogue 17000 (2018) values for the ECMA 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 NU1964-ECMA?
SKF NU 1964 ECMA is a single-row caged cylindrical roller bearing with 320 mm bore, 440 mm OD and 56 mm width per ISO 15. SKF lists C 693 kN, C0 1200 kN, Pu 110 kN, reference speed 1,500 r/min and limiting speed 2,000 r/min, mass about 26000 g.
What does the NU designation and ECMA suffix mean?
The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. 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 NU1964-ECMA 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 NU1964-ECMA 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.