NA49-32 bearing: complete specifications & equivalents
The NA49-32 is a ISO 1206 radial bearing sized 32 x 52 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 32 mm |
| Outer diameter D | 52 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 30.8 kN |
| Basic static load rating C0 | 51 kN |
| Fatigue load limit Pu | 6.3 kN |
| Reference speed (thermal) | 10000 rpm |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 160 g |
| Manufacturer designation | NA 49/32 |
| Standard | ISO 1206 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring); 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 & NA-49-series range
| Bore d | 1.26 in |
|---|---|
| Outer diameter D | 2.047 in |
| Width B | 0.787 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 10 mm |
| Smallest bore in NA-49-series | 10 mm |
| Largest outer diameter in NA-49-series | 190 mm |
| Width range across NA-49-series | 13–50 mm |
| Bore position in NA-49-series (smallest first) | 10 of 28 |
| Bore above smallest NA-49-series size | 22 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NA49-32 model number is decoded
In SKF catalogue PUB BU/P1 17000, NA 49/32 denotes a complete needle roller bearing for a 32 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 52 mm OD and 20 mm width. The NA 49/32 code gives bore 32 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. For life calculation, the 30.8/51 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.
Typical equipment & failure modes
Common applications
- agricultural implement pivots and cutter heads
- electric motor armature shafts with ground seats
- printing and paper-handling rollers
- gearbox shafts where the journal cannot be hardened on site
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- polymer cage deformation when the local temperature exceeds the 120 °C sustained limit
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- hard-particle indentation in unfiltered lubricant
- inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact
Selection pitfalls — read before you substitute
- At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.
- Hardness is load capacity: in families without an inner ring the 32 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.
- The quoted 30.8/51 kN ratings are SKF catalogue values for this exact execution (NA 49/32); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 30.8/51 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
What limits the service life of a NA 49/32?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 32 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NA 49/32?
A NA 49/32 measures 32 mm bore/Fw × 52 mm outside diameter × 20 mm width (1.26 × 2.047 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 30.8 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 160 g.
How is the NA 49/32 designation read?
The letters mark a machined-ring needle roller bearing with inner ring: 32 mm bore, 20 mm width, 52 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices.
Can the NA 49/32 run on an unhardened shaft?
Yes — that is the point of this family. The NA 49/32 carries its own hardened, ground inner ring on a 32 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring on 2026-09-26. Read our editorial & correction policy.