NN3024K bearing: complete specifications & equivalents
The NN3024K is a ISO 15 radial bearing sized 120 x 180 x 46 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 180 mm |
| Width B | 46 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 258 kN |
| Basic static load rating C0 | 390 kN |
| Fatigue load limit Pu | 42.5 kN |
| Limiting speed (mechanical) | 3300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3830 g |
| Manufacturer designation | NTN NN3024K |
| 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 | 4.724 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 1.811 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 30 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) | 19 of 40 |
| Bore above smallest NN3000-series size | 95 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3024K | 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 NN3024K model number is decoded
NTN lists NN3024K on the 120×180 mm envelope, 46 mm wide: a line-contact radial bearing with a machined or stamped steel cage per the precision execution and a grease limiting speed of 3,300 r/min. 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 120 mm, with 180 mm OD and 46 mm width from the ISO 15 general plan. 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 NN3024K. Speed ratio check: limiting 3,300 r/min is .85 of the 3,900 r/min oil value for NN3024K; grease-churn heating closes that gap as fill quantity rises. Provide axial location with an adjacent locating bearing rather than expecting the float cylindrical set to hold thrust on the 120 mm shaft.
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
- 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
- false brinelling on standby machines exposed to external vibration
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- At 120 mm bore, oil-lubricated arrangements toward 3,900 r/min need positive flow and drain design; the 3830 g NN3024K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Do not replace NN3024K with a deep-groove ball bearing on rating alone: line contact gives 258 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 258/390 kN pair here belongs to NN3024K as printed, not to the bare size.
- The 30.0 mm section at 120 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 46 mm-wide cavity.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 180 mm race brinells and releases as vibration within hours.
- The 258/390 kN ratings, 42.5 kN Pu and 3830 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3024K (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 NN3024K?
NN3024K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 120 mm bore, 180 mm OD and 46 mm width (4.724 × 7.087 × 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 258 kN, C0 390 kN, Pu 42.5 kN, grease limiting speed 3,300 r/min, oil 3,900 r/min, mass about 3830 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. NN3024K 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. NN3024K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3024K?
The K suffix denotes a 1:12 tapered bore. NN3024K 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 NN3024 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3024K?
NTN rates NN3024K at 3,300 r/min with grease and 3,900 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.