NNCL4956-CV bearing: complete specifications & equivalents
The NNCL4956-CV is a ISO 15 radial bearing sized 280 x 380 x 100 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 280 mm |
| Outer diameter D | 380 mm |
| Width B | 100 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 1210 kN |
| Basic static load rating C0 | 2700 kN |
| Fatigue load limit Pu | 255 kN |
| Reference speed (thermal) | 700 rpm |
| Limiting speed (mechanical) | 900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 33000 g |
| Manufacturer designation | SKF NNCL 4956 CV |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.4 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. 6.4 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. 6.4 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 & NNCL4900-series range
| Bore d | 11.024 in |
|---|---|
| Outer diameter D | 14.961 in |
| Width B | 3.937 in |
| ISO bore code | 56 |
| Radial section height (D−d)/2 | 50 mm |
| Smallest bore in NNCL4900-series | 60 mm |
| Largest outer diameter in NNCL4900-series | 540 mm |
| Width range across NNCL4900-series | 25–140 mm |
| Bore position in NNCL4900-series (smallest first) | 19 of 25 |
| Bore above smallest NNCL4900-series size | 220 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NNC4956-CV | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 280×380×100 mm and equivalent catalogue ratings; the NNC execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NNCF4956-CV | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 280×380×100 mm and equivalent catalogue ratings; the NNCF 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 NNCL4956-CV model number is decoded
NNCL4956-CV is the 280 mm bore entry in the NNCL4900 range: a 280×380×100 mm double-row full-complement cylindrical roller bearing with a full complement of extra rollers fitted in place of a cage, rated C 1210 kN / C0 2700 kN. Reading the NNCL prefix: a double-row full complement bearing with three integral flanges on the inner ring and no retaining ring in the smooth outer ring, which is free to pass over the roller set. This makes the execution non-locating: the outer ring can be displaced axially, like an NN design, to absorb shaft expansion. Reading the order-string suffix CV: the full-complement execution — extra rollers replace the cage, trading speed for maximum radial capacity and stiffness. Load-per-bore for the 280 mm seat is about 4.32 kN/mm, typical of dimension series 49 (compact heavy section); use C0 2700 kN for static checks such as crane hook blocks standing under load. Mounting: treat the outer ring as the floating element; keep the inner ring with its three flanges square on the shaft and relubricate through the outer-ring groove. A 280 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- steelmaking and heavy crane sheaves
- large offshore winch and hook blocks
- mining shovel and dragline pivots
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
- roller smearing between the uncaged rollers during slow skidding starts under heavy static 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
- uneven row loading from misalignment, concentrating fatigue on one row of the double complement
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- The NNCF/NNCL/NNC triplet shares the envelope and ratings but differs in outer-ring retention — one retaining ring, none, or two; selecting the wrong one changes the axial-locating scheme.
- Relubrication must reach both roller rows through the annular groove; blocked lube holes starve one row silently and show later as asymmetric raceway wear.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 100 mm-wide ring and concentrates load.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- The 1210/2700 kN ratings are SKF catalogue 17000 (2018) values for the CV 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 NNCL4956-CV?
SKF NNCL 4956 CV is a double-row full-complement cylindrical roller bearing with 280 mm bore, 380 mm OD and 100 mm width per ISO 15. SKF lists C 1210 kN, C0 2700 kN, Pu 255 kN, reference speed 700 r/min and limiting speed 900 r/min, mass about 33000 g.
What does the NNCL designation and CV suffix mean?
Suffix CV identifies the full-complement execution: the space a cage would occupy is filled with extra rollers, trading speed for maximum radial capacity and stiffness. Structurally this execution has a double-row full complement bearing with three integral flanges on the inner ring and no retaining ring in the smooth outer ring, which is free to pass over the roller set.
Can NNCL4956-CV take axial load and locate the shaft?
No — the smooth outer ring floats, making NNCL the non-locating member of the arrangement.
How does NNCL4956-CV compare with the other executions in the same envelope?
NNCF (one outer retaining ring, one-direction guidance), NNCL (no retaining ring, floating outer ring) and NNC (retaining rings both sides, two-direction location) share the ISO envelope and ratings but are not interchangeable in a locating arrangement.
What limits the service life of this bearing most often?
On full-complement bearings the dominant risks are roller smearing from skidding below minimum load and contamination; maintain minimum radial load, keep lubricant film thick and accelerate gently.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.4 double-row full complement cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.