NU220 bearing: complete specifications & equivalents
The NU220 is a ISO 15 radial bearing sized 100 x 180 x 34 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 100 mm |
| Outer diameter D | 180 mm |
| Width B | 34 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 285 kN |
| Basic static load rating C0 | 305 kN |
| Fatigue load limit Pu | 36.5 kN |
| Reference speed (thermal) | 4000 rpm |
| Limiting speed (mechanical) | 4500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3350 g |
| Manufacturer designation | NU 220 ECP |
| 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 | 3.937 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 1.339 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 40 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) | 18 of 39 |
| Bore above smallest NU2200-series size | 83 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6220-RSR | NSK | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6220 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6220-2RS | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6220-ZZ | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| N220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF N 220 ECP is a different execution with its own cage/flange configuration. |
| N220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF N 220 ECP is a different execution with its own cage/flange configuration. |
| N220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF N 220 ECP is a different execution with its own cage/flange configuration. |
| NJ220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 220 ECP is a different execution with its own cage/flange configuration. |
| NJ220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 220 ECP is a different execution with its own cage/flange configuration. |
| NJ220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 220 ECP is a different execution with its own cage/flange configuration. |
| NUP220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 220 ECP is a different execution with its own cage/flange configuration. |
| NUP220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 220 ECP is a different execution with its own cage/flange configuration. |
| NUP220-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 220 ECP is a different execution with its own cage/flange configuration. |
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 NU220 model number is decoded
NU220 is a single-row cylindrical roller bearing in the NU2200 family: line-contact rollers between ground inner and outer raceways, separated by a glass-fibre reinforced polyamide (PA66) cage, listed by SKF in SKF catalogue PUB BU/P1 17000. The code breaks down as type prefix NU (inner ring separable, no outer-ring ribs), series 22 (the wide), and bore code 20 = 100 mm; dimensions 100×180×34 mm therefore match the ISO 15 envelope. The SKF catalogue adds the ECP suffix for the standard glass-fibre reinforced polyamide cage; ECJ (pressed steel) and ECM (machined brass) are alternative executions with different speed and temperature ratings. Catalogue mass 3350 g for the 100×180×34 mm open execution covers the polymer cage and standard roller complement; steel or brass cage variants differ slightly in mass and carry their own order numbers. The outer ring has no ribs and cannot locate the shaft axially; pair NU220 with a locating bearing (e.g. deep-groove ball or angular contact) or use an NJ/NUP variant if one-direction location is required.
Typical equipment & failure modes
Common applications
- cement-kiln support-roller shafts
- wind-turbine gearbox intermediate shafts
- marine propulsion gearbox shafts
- heavy industrial gearbox 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
- 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 from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)
Selection pitfalls — read before you substitute
- Mount the 100 mm bore NU220 by induction heating of the inner ring (max 120 °C — the polymer cage sets the ceiling, not the steel); driving it home through the rollers brinells the raceway.
- The NU2200 series at 100 mm bore (180×34 mm) is the wide-section cylindrical roller with higher capacity but lower speed limit than the standard NU200 counterpart; do not substitute without re-checking shaft shoulder diameters and dn limit.
- The NU220 shares its ISO 15 envelope with other cylindrical bearings of the same code but is not a drop-in replacement for a ball bearing: it has no axial load capacity in the NU design, and a deep-groove bearing cannot replace its radial-capacity duty.
- Shaft and housing fillets must clear the bearing chamfer so the 34 mm-wide outer ring seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The 285/305 kN ratings are SKF catalogue 17000 values for the ECP polymer-cage execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of NU220 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 220 ECP designation when purchasing and match the execution to the speed and temperature requirements.
Frequently asked questions
What are the dimensions and catalogue data of NU220?
The NU 220 ECP is a single-row cylindrical roller bearing with 100 mm bore, 180 mm outer diameter and 34 mm width (3.937 × 7.087 × 1.339 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 285 kN, C0 305 kN, fatigue load limit Pu 36.5 kN, reference speed 4,000 r/min, limiting speed 4,500 r/min, mass about 3350 g. It is an open, separable bearing with a glass-fibre reinforced polyamide cage.
How does the NU220 bore code work?
The last two digits of NU220 are bore code 20, so 20 × 5 = 100 mm bore. The 180 mm OD and 34 mm width come from the ISO 15 dimension-series plan, shared with other cylindrical bearings of the same code.
What does the ECP suffix mean on NU220?
ECP stands for a glass-fibre reinforced polyamide cage (PA66), the SKF standard for this size. Alternative executions include ECJ (pressed steel cage) and ECM (machined brass cage), which have different speed and temperature ratings and are separate order numbers.
Can NU220 take axial load?
No — the NU design has no ribs on the outer ring and cannot support axial load in either direction. It is intended for pure radial load with axial location provided by adjacent components. If axial location is required, consider NJ (one-direction) or NUP (two-direction) variants, or pair the NU bearing with a thrust or angular-contact bearing.
How does NU220 compare with a ball bearing of the same bore?
A cylindrical roller bearing has line contact and much higher radial capacity than a ball bearing of the same bore, but it cannot take axial load in the NU design and is sensitive to misalignment (≈ 3–4 minutes of arc). Speed limits are generally lower than deep-groove ball bearings. A ball bearing cannot be dropped into a pure radial cylindrical-roller position without re-checking life and deflection, and vice versa.
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.