NUP3992-ECMA bearing: complete specifications & equivalents
The NUP3992-ECMA is a ISO 15 radial bearing sized 460 x 620 x 118 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 460 mm |
| Outer diameter D | 620 mm |
| Width B | 118 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 2050 kN |
| Basic static load rating C0 | 4550 kN |
| Fatigue load limit Pu | 375 kN |
| Reference speed (thermal) | 850 rpm |
| Limiting speed (mechanical) | 1300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 112000 g |
| Manufacturer designation | SKF NUP 3992 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 & NUP3900-series range
| Bore d | 18.11 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 4.646 in |
| ISO bore code | 92 |
| Radial section height (D−d)/2 | 80 mm |
| Smallest bore in NUP3900-series | 420 mm |
| Largest outer diameter in NUP3900-series | 620 mm |
| Width range across NUP3900-series | 106–118 mm |
| Bore position in NUP3900-series (smallest first) | 2 of 2 |
| Bore above smallest NUP3900-series size | 40 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NUP3992-ECMA model number is decoded
SKF NUP 3992 ECMA is a single-row caged cylindrical roller bearing sized 460×620×118 mm — a dimension series 39 (compact OD), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. 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. Selection arithmetic: C0/C ≈ 2.22 (4550 against 2050 kN), and the Pu figure 375 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 850 r/min thermal reference speed and 1,300 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.
Typical equipment & failure modes
Common applications
- large rolling-mill drive trains
- marine propulsion line shafts
- heavy turbogenerator rotor supports
- mining hoist and winder 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
- 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
- brinelling from static overload or impact during handling and mounting
Selection pitfalls — read before you substitute
- Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing
- The dimension series 39 (compact OD) envelope is shared with the N/NU/NJ/NUP executions of 3992, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 3992 ECMA 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.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 118 mm-wide ring and concentrates load.
- The 2050/4550 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 NUP3992-ECMA?
SKF NUP 3992 ECMA is a single-row caged cylindrical roller bearing with 460 mm bore, 620 mm OD and 118 mm width per ISO 15. SKF lists C 2050 kN, C0 4550 kN, Pu 375 kN, reference speed 850 r/min and limiting speed 1,300 r/min, mass about 112000 g.
What does the NUP 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 plus one integral flange and one loose flange ring on the inner ring.
Can NUP3992-ECMA take axial load and locate the shaft?
Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance.
How does NUP3992-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.