NN3052K bearing: complete specifications & equivalents
The NN3052K is a ISO 15 radial bearing sized 260 x 400 x 104 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 260 mm |
| Outer diameter D | 400 mm |
| Width B | 104 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1180 kN |
| Basic static load rating C0 | 1990 kN |
| Fatigue load limit Pu | 170 kN |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 45800 g |
| Manufacturer designation | NTN NN3052K |
| 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 | 10.236 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 4.094 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 70 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) | 30 of 40 |
| Bore above smallest NN3000-series size | 235 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3052K | 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 NN3052K model number is decoded
For pure radial duty on a 260 mm shaft NTN supplies NN3052K: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 1,500 r/min on grease and 1,700 r/min on oil. Digit by digit, NN3052K reads as NN (double row, ribbed inner ring, separable outer), ISO 15 series, and bore 260 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. The 70.0 mm radial section ((400−260)/2) frames the roller complement; capacity per millimetre of bore is about 4.5 kN/mm before application factors. Mass 45800 g for the 260×400×104 mm NN3052K 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 NN3052K.
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
- 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
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- At 260 mm bore, oil-lubricated arrangements toward 1,700 r/min need positive flow and drain design; the 45800 g NN3052K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The 70.0 mm section at 260 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 104 mm-wide cavity.
- The NN rib arrangement is not interchangeable with another prefix on the same 260 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 400×104 mm envelope matches.
- The 104 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 260 mm inner ring.
- The 70.0 mm section at 260 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 104 mm-wide cavity.
- The 1180/1990 kN ratings, 170 kN Pu and 45800 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3052K (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 NN3052K?
NN3052K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 260 mm bore, 400 mm OD and 104 mm width (10.236 × 15.748 × 4.094 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1180 kN, C0 1990 kN, Pu 170 kN, grease limiting speed 1,500 r/min, oil 1,700 r/min, mass about 45800 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. NN3052K 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. NN3052K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3052K?
The K suffix denotes a 1:12 tapered bore. NN3052K 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 NN3052 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3052K?
NTN rates NN3052K at 1,500 r/min with grease and 1,700 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.