NNF5052-B-2LS bearing: complete specifications & equivalents
The NNF5052-B-2LS is a ISO 15 radial bearing sized 260 x 400 x 190 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 260 mm |
| Outer diameter D | 400 mm |
| Width B | 190 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 2420 kN |
| Basic static load rating C0 | 4650 kN |
| Fatigue load limit Pu | 455 kN |
| Reference speed (thermal) | 300 rpm |
| Limiting speed (mechanical) | 300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 86000 g |
| Manufacturer designation | SKF NNF 5052 B-2LS |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.5 sealed double-row full complement cylindrical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.5 sealed double-row full complement 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. 6.5 sealed double-row full complement 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 & NNF5000-series range
| Bore d | 10.236 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 7.48 in |
| ISO bore code | 52 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NNF5000-series | 20 mm |
| Largest outer diameter in NNF5000-series | 420 mm |
| Width range across NNF5000-series | 30–190 mm |
| Bore position in NNF5000-series (smallest first) | 30 of 31 |
| Bore above smallest NNF5000-series size | 240 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NNCF5052-CV | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Open full-complement counterpart on the same 260×400×190 mm envelope; this B-2LS row is sealed both sides and grease-packed with a lower limiting speed, and its catalogue ratings differ from the open execution. |
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 NNF5052-B-2LS model number is decoded
Ordering number SKF NNF 5052 B-2LS resolves to a 260×400×190 mm sealed double-row full-complement cylindrical roller bearing (dimension series 50 (compact heavy section, wide)); a double-row full complement bearing with contact seals on both sides, three integral inner-ring flanges, an annular lube groove in the outer ring and additional lubrication holes in the inner ring, delivered grease-packed. Reading the NNF prefix: a double-row full complement bearing with contact seals on both sides, three integral inner-ring flanges, an annular lube groove in the outer ring and additional lubrication holes in the inner ring, delivered grease-packed. This makes the execution a sealed locating unit for very heavy radial loads; the sealed-for-life execution is the classic crane-sheave bearing. Reading the order-string suffix B-2LS: nitrile-rubber contact seals on both sides of a grease-packed full-complement unit. With C 2420 kN and C0 4650 kN, size the bearing on the 260×400 mm ISO 15 envelope and check the 455 kN Pu against the equivalent-load floor; SKF publishes only a limiting speed of 300 r/min for this sealed execution — the seal contact and packed grease, not a thermal reference speed, set the ceiling. Mounting: mount as a complete sealed unit — never wash out the factory grease; the seals set the speed ceiling, and relubrication, where specified, goes through the ring grooves. A 260 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- large offshore hook blocks and jib sheaves
- heavy dock and shipyard crane systems
- mining dragline and shovel rope sheaves
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
- seal-lip wear and grease loss in dusty crane and construction service after the relubrication interval is exceeded
- 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
- grease degradation inside the sealed unit after long high-temperature periods, invisible until noise rises
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- The sealed NNF unit is packed for life with the correct grease — do not heat it above the seal limit or wash it before mounting; damaged lip seals invalidate the heavy-load duty.
- The B1 width (189 mm inner-assembly width) differs from the overall B 190 mm; check housing and spacer geometry against both values.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 190 mm-wide ring and concentrates load.
- Catalogue reference and limiting speeds are different criteria, though only the limiting speed is published for this sealed unit: observe the mechanical ceiling even when thermal calculations allow more.
- The 2420/4650 kN ratings are SKF catalogue 17000 (2018) values for the B-2LS 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 NNF5052-B-2LS?
SKF NNF 5052 B-2LS is a sealed double-row full-complement cylindrical roller bearing with 260 mm bore, 400 mm OD and 190 mm width per ISO 15. SKF lists C 2420 kN, C0 4650 kN, Pu 455 kN, limiting speed 300 r/min (sealed execution), mass about 86000 g. Inner-assembly width B1 is 189 mm.
What does the NNF designation and B-2LS suffix mean?
The B-2LS suffix denotes nitrile-rubber contact seals on both sides of a grease-packed full-complement unit. Structurally this execution has a double-row full complement bearing with contact seals on both sides, three integral inner-ring flanges, an annular lube groove in the outer ring and additional lubrication holes in the inner ring, delivered grease-packed.
Can NNF5052-B-2LS take axial load and locate the shaft?
The sealed NNF unit can guide light axial loads in both directions via the flanged inner ring, but its primary duty is very heavy radial load in sealed positions.
How does NNF5052-B-2LS compare with the other executions in the same envelope?
The sealed NNF execution shares its envelope with the open NNCF/NNCL/NNC full-complement bearings but is delivered grease-packed with contact seals and a much lower speed ceiling.
Does the sealed NNF bearing need relubrication?
NNF bearings are delivered grease-packed and sealed for long service; where the design provides relubrication grooves/holes, replenish through them at the prescribed interval. Never wash the bearing out or exceed the seal-limited speed.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.5 sealed double-row full complement cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.