NN3076K bearing: complete specifications & equivalents
The NN3076K is a ISO 15 radial bearing sized 380 x 560 x 135 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 380 mm |
| Outer diameter D | 560 mm |
| Width B | 135 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1870 kN |
| Basic static load rating C0 | 3450 kN |
| Fatigue load limit Pu | 265 kN |
| Limiting speed (mechanical) | 940 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 109000 g |
| Manufacturer designation | NTN NN3076K |
| 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 | 14.961 in |
|---|---|
| Outer diameter D | 22.047 in |
| Width B | 5.315 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 90 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) | 36 of 40 |
| Bore above smallest NN3000-series size | 355 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3076K | 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 NN3076K model number is decoded
NN3076K belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E: line-contact rollers between ground raceways for a 1870 kN dynamic rating in the 380 mm bore. 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 380 mm, with 560 mm OD and 135 mm width from the ISO 15 general plan. The 135 mm width and 90.0 mm section put the NN3000 series in the standard section; wide 22/23 variants at the same bore change OD, width and heat generation and are not drop-in swaps. Mass 109000 g for the 380×560×135 mm NN3076K execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. 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 NN3076K.
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
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- 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
- At 380 mm bore, oil-lubricated arrangements toward 1,100 r/min need positive flow and drain design; the 109000 g NN3076K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 1870/3450 kN pair here belongs to NN3076K as printed, not to the bare size.
- The NN rib arrangement is not interchangeable with another prefix on the same 380 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 560×135 mm envelope matches.
- Grease limiting speed 940 r/min and oil 1,100 r/min are different limits for NN3076K: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Open NN3076K 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 380 mm contact.
- The 1870/3450 kN ratings, 265 kN Pu and 109000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3076K (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 NN3076K?
NN3076K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 380 mm bore, 560 mm OD and 135 mm width (14.961 × 22.047 × 5.315 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1870 kN, C0 3450 kN, Pu 265 kN, grease limiting speed 940 r/min, oil 1,100 r/min, mass about 109000 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. NN3076K 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. NN3076K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3076K?
The K suffix denotes a 1:12 tapered bore. NN3076K 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 NN3076 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3076K?
NTN rates NN3076K at 940 r/min with grease and 1,100 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.