NN3012K bearing: complete specifications & equivalents
The NN3012K is a ISO 15 radial bearing sized 60 x 95 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 | 60 mm |
| Outer diameter D | 95 mm |
| Width B | 26 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 78.5 kN |
| Basic static load rating C0 | 102 kN |
| Fatigue load limit Pu | 12.4 kN |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 683 g |
| Manufacturer designation | NTN NN3012K |
| 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 | 2.362 in |
|---|---|
| Outer diameter D | 3.74 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) | 8 of 40 |
| Bore above smallest NN3000-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3012K | 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 NN3012K model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, NN3012K appears as a 60 mm bore single-row cylindrical roller bearing (78.5 kN C / 102 kN C0) with a machined or stamped steel cage per the precision execution, listed to the ISO 15 boundary plan. On the NTN nameplate NN states which ring carries the ribs, which determines whether NN3012K floats or locates; the numeric remainder is the ISO 15 series and 60 mm bore reference, not a fit or clearance instruction. NTN prints two speed ceilings: 6,700 r/min grease and 7,900 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 60 mm bore. Rating life at 78.5 kN C assumes clean oil and adequate film; the 12.4 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NN3012K non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- high-speed turbine and turbo-blower rotor supports
- coordinate-measuring and semiconductor-equipment drives
- machine-tool main spindles requiring high radial stiffness
- precision gearbox and indexing-drive shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- brinelling from static overload or impact during handling
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Induction-heat the 60 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 95 mm raceway.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN3012K skids at 6,700 r/min and fails by smearing long before L10 fatigue.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 78.5/102 kN pair here belongs to NN3012K as printed, not to the bare size.
- The NN rib arrangement is not interchangeable with another prefix on the same 60 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 95×26 mm envelope matches.
- The K tapered bore of NN3012K is driven up to a measured clearance: skipping the drive-up procedure in favour of a normal press fit leaves the precision spindle set either preloaded hot or loose under load.
- The 78.5/102 kN ratings, 12.4 kN Pu and 683 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3012K (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 NN3012K?
NN3012K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 60 mm bore, 95 mm OD and 26 mm width (2.362 × 3.74 × 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 78.5 kN, C0 102 kN, Pu 12.4 kN, grease limiting speed 6,700 r/min, oil 7,900 r/min, mass about 683 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. NN3012K 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. NN3012K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3012K?
The K suffix denotes a 1:12 tapered bore. NN3012K 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 NN3012 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3012K?
NTN rates NN3012K at 6,700 r/min with grease and 7,900 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.