NNU4922K bearing: complete specifications & equivalents
The NNU4922K is a ISO 15 radial bearing sized 110 x 150 x 40 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 110 mm |
| Outer diameter D | 150 mm |
| Width B | 40 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 152 kN |
| Basic static load rating C0 | 284 kN |
| Fatigue load limit Pu | 32 kN |
| Limiting speed (mechanical) | 3900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1900 g |
| Manufacturer designation | NTN NNU4922K |
| 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 | 4.331 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.575 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 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) | 3 of 26 |
| Bore above smallest NNU4900-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NNU4922K | 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 NNU4922K model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, NNU4922K appears as a 110 mm bore single-row cylindrical roller bearing (152 kN C / 284 kN C0) with a machined or stamped steel cage per the precision execution, listed to the ISO 15 boundary plan. On the NTN nameplate NNU states which ring carries the ribs, which determines whether NNU4922K floats or locates; the numeric remainder is the ISO 15 series and 110 mm bore reference, not a fit or clearance instruction. Double-row NNU precision cylindrical roller bearing: ribbed outer ring with a separable inner ring, two roller rows for high radial stiffness on machine-tool spindles; the K suffix is a 1:12 tapered bore — mounted on a tapered seat or adapter sleeve and driven up to a precise radial clearance/preload; precision classes P5/P4/P2 and clearance are ordered separately. With the inner ring rotating, catalogue practice is a m6/n6 shaft seat and an H7/H6 housing; the outer ring must remain free to creep slightly axially in non-locating NNU arrangements. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NNU4922K non-locating position preloads the bearing when the shaft grows.
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
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- brinelling from static overload or impact during handling
- brinelling from static overload or impact during handling
Selection pitfalls — read before you substitute
- Induction-heat the 110 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 150 mm raceway.
- Wide (22/23) and light (10/49) executions at 110 mm bore share bore but not OD/width; check the full NNU4900 series code before substituting, because housing and shoulder geometry will not interchange.
- The 40 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 110 mm inner ring.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NNU4922K skids at 3,900 r/min and fails by smearing long before L10 fatigue.
- The 40 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 110 mm inner ring.
- The 152/284 kN ratings, 32 kN Pu and 1900 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NNU4922K (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 NNU4922K?
NNU4922K is an NTN NNU double-row precision cylindrical roller bearing to ISO 15: 110 mm bore, 150 mm OD and 40 mm width (4.331 × 5.906 × 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 152 kN, C0 284 kN, Pu 32 kN, grease limiting speed 3,900 r/min, oil 4,600 r/min, mass about 1900 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. NNU4922K 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. NNU4922K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NNU bearing like NNU4922K?
The K suffix denotes a 1:12 tapered bore. NNU4922K 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 NNU4922 execution of the same envelope mounts on a plain seat.
What do Fw and Ew mean for NNU4922K?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 123 mm. The nominal bore/OD remain 110/150 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 3,900 r/min grease / 4,600 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.