NN3011 bearing: complete specifications & equivalents
The NN3011 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 | 651 g |
| Manufacturer designation | NTN NN3011 |
| 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 | 11 |
| 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 |
|---|---|---|---|
| NN3011 | 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 NN3011 model number is decoded
For pure radial duty on a 55 mm shaft NTN supplies NN3011: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 7,300 r/min on grease and 8,600 r/min on oil. 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. NTN prints two speed ceilings: 7,300 r/min grease and 8,600 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 55 mm bore. Selection arithmetic: Pu 11.8 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.25 (96.5/77 kN) shows the high-static-capacity proportioning of this 55 mm bore. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NN3011 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- coordinate-measuring and semiconductor-equipment drives
- machine-tool main spindles requiring high radial stiffness
- precision gearbox and indexing-drive shafts
- high-rpm motorised grinding and milling spindles
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- 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 NN3011.
- Grease limiting speed 7,300 r/min and oil 8,600 r/min are different limits for NN3011: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- 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.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 90 mm race brinells and releases as vibration within hours.
- Double-row NN precision bearings are typically ordered P5/P4 with specific radial clearance for spindle preloading; a P0/CN NN3011 does not substitute a precision-class execution.
- The 77/96.5 kN ratings, 11.8 kN Pu and 651 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3011 (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 NN3011?
NN3011 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 651 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. NN3011 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. NN3011 is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3011?
NN3011 has a cylindrical bore and mounts on a plain machined shaft seat; a K execution (1:12 taper) exists in the NN3000 series when preload must be set by drive-up on a tapered seat.
What speeds and lubrication apply to NN3011?
NTN rates NN3011 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.