NU20-710-ECMA-HB1 bearing: complete specifications & equivalents
The NU20-710-ECMA-HB1 is a ISO 15 radial bearing sized 710 x 1030 x 185 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 710 mm |
| Outer diameter D | 1030 mm |
| Width B | 185 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 5940 kN |
| Basic static load rating C0 | 12000 kN |
| Fatigue load limit Pu | 815 kN |
| Reference speed (thermal) | 480 rpm |
| Limiting speed (mechanical) | 700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 540000 g |
| Manufacturer designation | SKF NU 20/710 ECMA/HB1 |
| 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 & NU2000-series range
| Bore d | 27.953 in |
|---|---|
| Outer diameter D | 40.551 in |
| Width B | 7.283 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 160 mm |
| Smallest bore in NU2000-series | 300 mm |
| Largest outer diameter in NU2000-series | 1220 mm |
| Width range across NU2000-series | 95–212 mm |
| Bore position in NU2000-series (smallest first) | 9 of 12 |
| Bore above smallest NU2000-series size | 410 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU20-710-ECMA-HB1 model number is decoded
For a 710 mm shaft, SKF lists NU20-710-ECMA-HB1 as single-row caged cylindrical roller: 1030 mm OD, 185 mm wide, Pu 815 kN, the catalogue lists 480 r/min thermal reference speed and 700 r/min mechanical limiting speed. Structurally, the NU design 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. In arrangement terms it 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 ECMA/HB1: the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 710 mm seat is about 8.37 kN/mm, typical of dimension series 20 (light section for large shafts); use C0 12000 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 710 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
- 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
- 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 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/710, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/710 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- The 5940/12000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 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 NU20-710-ECMA-HB1?
SKF NU 20/710 ECMA/HB1 is a single-row caged cylindrical roller bearing with 710 mm bore, 1030 mm OD and 185 mm width per ISO 15. SKF lists C 5940 kN, C0 12000 kN, Pu 815 kN, reference speed 480 r/min and limiting speed 700 r/min, mass about 540000 g.
What does the NU designation and ECMA/HB1 suffix mean?
The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. 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 NU20-710-ECMA-HB1 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 NU20-710-ECMA-HB1 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.