NN3072K bearing: complete specifications & equivalents
The NN3072K is a ISO 15 radial bearing sized 360 x 540 x 134 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 360 mm |
| Outer diameter D | 540 mm |
| Width B | 134 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1830 kN |
| Basic static load rating C0 | 3300 kN |
| Fatigue load limit Pu | 258 kN |
| Limiting speed (mechanical) | 1000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 103000 g |
| Manufacturer designation | NTN NN3072K |
| 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 | 14.173 in |
|---|---|
| Outer diameter D | 21.26 in |
| Width B | 5.276 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) | 35 of 40 |
| Bore above smallest NN3000-series size | 335 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3072K | 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 NN3072K model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, NN3072K appears as a 360 mm bore single-row cylindrical roller bearing (1830 kN C / 3300 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 NN3072K floats or locates; the numeric remainder is the ISO 15 series and 360 mm bore reference, not a fit or clearance instruction. NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of NN3072K. The 360 mm (14.173 in) bore and 540 mm (21.26 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 134 mm-wide ring. Keep the open bearing wrapped until fitting: the line-contact raceways of the 360 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.
Typical equipment & failure modes
Common applications
- precision gearbox and indexing-drive shafts
- high-rpm motorised grinding and milling spindles
- CNC lathe and machining-centre spindle radial sets
- precision rotary-table and dividing-head bearings
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- rolling-contact fatigue after the catalogue L10 life is exceeded
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- At 360 mm bore, oil-lubricated arrangements toward 1,200 r/min need positive flow and drain design; the 103000 g NN3072K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 540 mm race brinells and releases as vibration within hours.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN3072K skids at 1,000 r/min and fails by smearing long before L10 fatigue.
- The K tapered bore of NN3072K 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.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 540 mm race brinells and releases as vibration within hours.
- The 1830/3300 kN ratings, 258 kN Pu and 103000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3072K (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 NN3072K?
NN3072K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 360 mm bore, 540 mm OD and 134 mm width (14.173 × 21.26 × 5.276 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1830 kN, C0 3300 kN, Pu 258 kN, grease limiting speed 1,000 r/min, oil 1,200 r/min, mass about 103000 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. NN3072K 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. NN3072K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3072K?
The K suffix denotes a 1:12 tapered bore. NN3072K 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 NN3072 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3072K?
NTN rates NN3072K at 1,000 r/min with grease and 1,200 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.