NN3006K bearing: complete specifications & equivalents
The NN3006K is a ISO 15 radial bearing sized 30 x 55 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 30 mm |
| Outer diameter D | 55 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 34 kN |
| Basic static load rating C0 | 37 kN |
| Fatigue load limit Pu | 4.55 kN |
| Limiting speed (mechanical) | 12000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 193 g |
| Manufacturer designation | NTN NN3006K |
| 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 | 1.181 in |
|---|---|
| Outer diameter D | 2.165 in |
| Width B | 0.748 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 12.5 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) | 2 of 40 |
| Bore above smallest NN3000-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3006K | 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 NN3006K model number is decoded
For pure radial duty on a 30 mm shaft NTN supplies NN3006K: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 12,000 r/min on grease and 15,000 r/min on oil. Digit by digit, NN3006K reads as NN (double row, ribbed inner ring, separable outer), ISO 15 series, and bore 30 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. At 15,000 r/min with oil versus 12,000 r/min with grease (a 3,000 r/min band), lubrication choice for NN3006K is a thermal decision, not just a sealing one. Thermal planning around the 12,000 r/min grease ceiling should include the cage type (a machined or stamped steel cage per the precision execution) and oil-flow option to 15,000 r/min for continuously high-duty 30 mm positions. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NN3006K.
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 wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- brinelling from static overload or impact during handling
Selection pitfalls — read before you substitute
- On this 30 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 NN3006K.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN3006K skids at 12,000 r/min and fails by smearing long before L10 fatigue.
- Do not replace NN3006K with a deep-groove ball bearing on rating alone: line contact gives 34 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Grease limiting speed 12,000 r/min and oil 15,000 r/min are different limits for NN3006K: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Grease limiting speed 12,000 r/min and oil 15,000 r/min are different limits for NN3006K: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 34/37 kN ratings, 4.55 kN Pu and 193 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3006K (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 NN3006K?
NN3006K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 30 mm bore, 55 mm OD and 19 mm width (1.181 × 2.165 × 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 34 kN, C0 37 kN, Pu 4.55 kN, grease limiting speed 12,000 r/min, oil 15,000 r/min, mass about 193 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. NN3006K 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. NN3006K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3006K?
The K suffix denotes a 1:12 tapered bore. NN3006K 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 NN3006 execution of the same envelope mounts on a plain seat.
What do Fw and Ew mean for NN3006K?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Ew 48.535 mm. The nominal bore/OD remain 30/55 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 12,000 r/min grease / 15,000 r/min oil.
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.