NU1018-ML bearing: complete specifications & equivalents
The NU1018-ML is a ISO 15 radial bearing sized 90 x 140 x 24 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 90 mm |
| Outer diameter D | 140 mm |
| Width B | 24 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 80.9 kN |
| Basic static load rating C0 | 104 kN |
| Fatigue load limit Pu | 12.7 kN |
| Reference speed (thermal) | 5600 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1350 g |
| Manufacturer designation | SKF NU 1018 ML |
| 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 & NU1000-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 0.945 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in NU1000-series | 25 mm |
| Largest outer diameter in NU1000-series | 1090 mm |
| Width range across NU1000-series | 12–150 mm |
| Bore position in NU1000-series (smallest first) | 14 of 45 |
| Bore above smallest NU1000-series size | 65 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ1018-ML | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 90×140×24 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
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 NU1018-ML model number is decoded
For a 90 mm shaft, SKF lists NU1018-ML as single-row caged cylindrical roller: 140 mm OD, 24 mm wide, Pu 12.7 kN, the catalogue lists 5,600 r/min thermal reference speed and 8,500 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. The ML suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Selection arithmetic: C0/C ≈ 1.29 (104 against 80.9 kN), and the Pu figure 12.7 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 5,600 r/min thermal reference speed and 8,500 r/min mechanical limiting speed. 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 90 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- heavy gearbox and pinion shafts
- large pump and blower rotors
- rolling-mill auxiliary drive shafts
- paper-machine press rolls
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
- smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load
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 10 (extra-slim OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 1018, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 1018 ML 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.
- Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 140 mm raceway.
- The 80.9/104 kN ratings are SKF catalogue 17000 (2018) values for the ML 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 NU1018-ML?
SKF NU 1018 ML is a single-row caged cylindrical roller bearing with 90 mm bore, 140 mm OD and 24 mm width per ISO 15. SKF lists C 80.9 kN, C0 104 kN, Pu 12.7 kN, reference speed 5,600 r/min and limiting speed 8,500 r/min, mass about 1350 g.
What does the NU designation and ML suffix mean?
The ML 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 NU1018-ML 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 NU1018-ML 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.