NN3048K bearing: complete specifications & equivalents
The NN3048K is a ISO 15 radial bearing sized 240 x 360 x 92 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 240 mm |
| Outer diameter D | 360 mm |
| Width B | 92 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 945 kN |
| Basic static load rating C0 | 1600 kN |
| Fatigue load limit Pu | 140 kN |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 31600 g |
| Manufacturer designation | NTN NN3048K |
| 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 | 9.449 in |
|---|---|
| Outer diameter D | 14.173 in |
| Width B | 3.622 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 60 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) | 29 of 40 |
| Bore above smallest NN3000-series size | 215 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3048K | 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 NN3048K model number is decoded
NN3048K belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E: line-contact rollers between ground raceways for a 945 kN dynamic rating in the 240 mm bore. Reading the code: NN for the double-row precision type, then the ISO 15 diameter/width series and the bore code — ×5 = 240 mm (00–03 use the 10/12/15/17 exception table). Minimum radial load matters: an unloaded NN3048K at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Speed ratio check: limiting 1,600 r/min is .84 of the 1,900 r/min oil value for NN3048K; grease-churn heating closes that gap as fill quantity rises. Keep the open bearing wrapped until fitting: the line-contact raceways of the 240 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.
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
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- false brinelling on standby machines exposed to external vibration
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- At 240 mm bore, oil-lubricated arrangements toward 1,900 r/min need positive flow and drain design; the 31600 g NN3048K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Open NN3048K 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 240 mm contact.
- The 92 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 240 mm inner ring.
- The K tapered bore of NN3048K 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.
- Do not replace NN3048K with a deep-groove ball bearing on rating alone: line contact gives 945 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 945/1600 kN ratings, 140 kN Pu and 31600 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3048K (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 NN3048K?
NN3048K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 240 mm bore, 360 mm OD and 92 mm width (9.449 × 14.173 × 3.622 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 945 kN, C0 1600 kN, Pu 140 kN, grease limiting speed 1,600 r/min, oil 1,900 r/min, mass about 31600 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. NN3048K 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. NN3048K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3048K?
The K suffix denotes a 1:12 tapered bore. NN3048K 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 NN3048 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3048K?
NTN rates NN3048K at 1,600 r/min with grease and 1,900 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.