NNU4932K bearing: complete specifications & equivalents
The NNU4932K is a ISO 15 radial bearing sized 160 x 220 x 60 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 160 mm |
| Outer diameter D | 220 mm |
| Width B | 60 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 395 kN |
| Basic static load rating C0 | 740 kN |
| Fatigue load limit Pu | 74 kN |
| Limiting speed (mechanical) | 2600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6230 g |
| Manufacturer designation | NTN NNU4932K |
| 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 & NNU4900-series range
| Bore d | 6.299 in |
|---|---|
| Outer diameter D | 8.661 in |
| Width B | 2.362 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 30 mm |
| Smallest bore in NNU4900-series | 100 mm |
| Largest outer diameter in NNU4900-series | 650 mm |
| Width range across NNU4900-series | 40–170 mm |
| Bore position in NNU4900-series (smallest first) | 8 of 26 |
| Bore above smallest NNU4900-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NNU4932K | 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 NNU4932K model number is decoded
NNU4932K is the extra-light (10/49) section of the NTN NNU4900 dimension series for a 160 mm shaft — 395 kN of basic dynamic capacity in a 6230 g, open bearing. Digit by digit, NNU4932K reads as NNU (double row, ribbed outer ring, separable inner), ISO 15 series, and bore 160 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. At 3,100 r/min with oil versus 2,600 r/min with grease (a 500 r/min band), lubrication choice for NNU4932K is a thermal decision, not just a sealing one. Rating life at 395 kN C assumes clean oil and adequate film; the 74 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NNU4932K non-locating position preloads the bearing when the shaft grows.
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
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- fretting corrosion on a loose rotating shaft seat
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- At 160 mm bore, oil-lubricated arrangements toward 3,100 r/min need positive flow and drain design; the 6230 g NNU4932K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The 60 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 160 mm inner ring.
- The 30.0 mm section at 160 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 60 mm-wide cavity.
- The K tapered bore of NNU4932K 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.
- Grease limiting speed 2,600 r/min and oil 3,100 r/min are different limits for NNU4932K: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 395/740 kN ratings, 74 kN Pu and 6230 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NNU4932K (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 NNU4932K?
NNU4932K is an NTN NNU double-row precision cylindrical roller bearing to ISO 15: 160 mm bore, 220 mm OD and 60 mm width (6.299 × 8.661 × 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 395 kN, C0 740 kN, Pu 74 kN, grease limiting speed 2,600 r/min, oil 3,100 r/min, mass about 6230 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. NNU4932K is the NNU 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. NNU4932K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NNU bearing like NNU4932K?
The K suffix denotes a 1:12 tapered bore. NNU4932K 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 NNU4932 execution of the same envelope mounts on a plain seat.
What do Fw and Ew mean for NNU4932K?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 178.5 mm, Ew 206.5169 mm. The nominal bore/OD remain 160/220 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,600 r/min grease / 3,100 r/min oil.
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.