NA6912 bearing: complete specifications & equivalents
The NA6912 is a ISO 1206 radial bearing sized 60 x 85 x 45 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 60 mm |
| Outer diameter D | 85 mm |
| Width B | 45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 93.5 kN |
| Basic static load rating C0 | 204 kN |
| Fatigue load limit Pu | 25 kN |
| Reference speed (thermal) | 6000 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 810 g |
| Manufacturer designation | NA 6912 |
| 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-69-series range
| Bore d | 2.362 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 1.772 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 12.5 mm |
| Smallest bore in NA-69-series | 12 mm |
| Largest outer diameter in NA-69-series | 130 mm |
| Width range across NA-69-series | 22–63 mm |
| Bore position in NA-69-series (smallest first) | 15 of 22 |
| Bore above smallest NA-69-series size | 48 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NA6912 model number is decoded
NA 6912 provides the full machined-ring needle roller construction: ground inner ring on a 60 mm seat, flanged outer ring at 85 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 60 mm bore (d), 45 mm width; the 85 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 60 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 45 mm assembly for free rotation before applying load.
Typical equipment & failure modes
Common applications
- electric motor armature shafts with ground seats
- printing and paper-handling rollers
- gearbox shafts where the journal cannot be hardened on site
- wheel and lever pivots needing a replaceable inner ring
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- polymer cage deformation when the local temperature exceeds the 120 °C sustained limit
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- corrosion pitting from condensation in intermittently operated machinery
- inner-ring raceway spalling after the narrow ring section runs hot with excessive interference
Selection pitfalls — read before you substitute
- Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.
- Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.
- Hardness is load capacity: in families without an inner ring the 60 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 93.5/204 kN ratings and 810 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
What does NA 6912 mean in SKF part numbering?
The letters mark a machined-ring needle roller bearing with inner ring: 60 mm bore, 45 mm width, 85 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices.
Does the NA 6912 need a hardened and ground shaft?
Yes — that is the point of this family. The NA 6912 carries its own hardened, ground inner ring on a 60 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable.
What mounting mistakes ruin a NA 6912?
Mount the inner ring on the 60 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth.
Is the NA 6912 sealed?
No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number.
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.