NN3011K bearing: complete specifications & equivalents
The NN3011K is a ISO 15 radial bearing sized 55 x 90 x 26 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 90 mm |
| Width B | 26 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 77 kN |
| Basic static load rating C0 | 96.5 kN |
| Fatigue load limit Pu | 11.8 kN |
| Limiting speed (mechanical) | 7300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 631 g |
| Manufacturer designation | NTN NN3011K |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & NN3000-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 1.024 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 17.5 mm |
| Smallest bore in NN3000-series | 25 mm |
| Largest outer diameter in NN3000-series | 680 mm |
| Width range across NN3000-series | 16–163 mm |
| Bore position in NN3000-series (smallest first) | 7 of 40 |
| Bore above smallest NN3000-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3011K | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NN3011K model number is decoded
The NTN order number NN3011K denotes a 55×90×26 mm (2.165 × 3.543 × 1.024 in) cylindrical roller bearing in the NN3000 family, a machined or stamped steel cage per the precision execution. The leading NN defines the rib arrangement (double row, ribbed inner ring, separable outer); the dimension-series digits and the two-digit bore code resolve to 55 mm, with 90 mm OD and 26 mm width from the ISO 15 general plan. Double-row NN precision cylindrical roller bearing: ribbed inner ring with a separable outer ring, two roller rows for high radial stiffness on machine-tool spindles; the K suffix is a 1:12 tapered bore — mounted on a tapered seat or adapter sleeve and driven up to a precise radial clearance/preload; precision classes P5/P4/P2 and clearance are ordered separately. The 55 mm (2.165 in) bore and 90 mm (3.543 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 26 mm-wide ring. Housing and shaft fillets must clear the ring chamfers of NN3011K; an oversized radius locks the ring on its face and tilts the 26 mm-wide seat.
Typical equipment & failure modes
Common applications
- precision rotary-table and dividing-head bearings
- high-speed turbine and turbo-blower rotor supports
- coordinate-measuring and semiconductor-equipment drives
- machine-tool main spindles requiring high radial stiffness
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage distortion after a mounting blow carried through the roller set
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- On this 55 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting NN3011K.
- The NN rib arrangement is not interchangeable with another prefix on the same 55 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 90×26 mm envelope matches.
- Open NN3011K units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 55 mm contact.
- Do not replace NN3011K with a deep-groove ball bearing on rating alone: line contact gives 77 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The 26 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 55 mm inner ring.
- The 77/96.5 kN ratings, 11.8 kN Pu and 631 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3011K (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.
Frequently asked questions
What are the dimensions and catalogue data of NN3011K?
NN3011K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 55 mm bore, 90 mm OD and 26 mm width (2.165 × 3.543 × 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 77 kN, C0 96.5 kN, Pu 11.8 kN, grease limiting speed 7,300 r/min, oil 8,600 r/min, mass about 631 g. It is open, with a machined or stamped steel cage per the precision execution.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
NN and NNU are double-row precision designs rather than single-row rib variants: NN has a ribbed inner ring and separable outer ring, NNU the reverse; both give high radial stiffness for spindles and are commonly ordered with P5/P4 precision and a K 1:12 tapered bore for preload setting. NN3011K is the NN execution.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NN3011K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3011K?
The K suffix denotes a 1:12 tapered bore. NN3011K mounts on a tapered shaft seat or adapter sleeve and is driven up to a measured residual clearance or preload — this is how precision spindle bearings achieve stiffness without locknut guesswork; the cylindrical-bore NN3011 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3011K?
NTN rates NN3011K at 7,300 r/min with grease and 8,600 r/min with oil. The grease figure is the cage/film mechanical ceiling; the oil figure assumes circulating or carefully supplied oil that removes heat from the line-contact zone.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.