NN4930 bearing: complete specifications & equivalents
The NN4930 is a ISO 15 radial bearing sized 150 x 210 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 | 150 mm |
| Outer diameter D | 210 mm |
| Width B | 60 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 380 kN |
| Basic static load rating C0 | 690 kN |
| Fatigue load limit Pu | 70.5 kN |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 5900 g |
| Manufacturer designation | NTN NN4930 |
| 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 & NN4900-series range
| Bore d | 5.906 in |
|---|---|
| Outer diameter D | 8.268 in |
| Width B | 2.362 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 30 mm |
| Smallest bore in NN4900-series | 100 mm |
| Largest outer diameter in NN4900-series | 440 mm |
| Width range across NN4900-series | 40–118 mm |
| Bore position in NN4900-series (smallest first) | 7 of 18 |
| Bore above smallest NN4900-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN4930 | 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 NN4930 model number is decoded
NN4930 belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E: line-contact rollers between ground raceways for a 380 kN dynamic rating in the 150 mm bore. Digit by digit, NN4930 reads as NN (double row, ribbed inner ring, separable outer), ISO 15 series, and bore 150 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. With C 380 kN and C0 690 kN (C0/C ≈ 1.82) the bearing is proportioned for heavy radial load; the NU design carries no axial load and floats axially on both sides. Equivalent-load planning treats NN4930 as a pure radial bearing: keep P below 380 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. Housing and shaft fillets must clear the ring chamfers of NN4930; an oversized radius locks the ring on its face and tilts the 60 mm-wide seat.
Typical equipment & failure modes
Common applications
- CNC lathe and machining-centre spindle radial sets
- precision rotary-table and dividing-head bearings
- high-speed turbine and turbo-blower rotor supports
- coordinate-measuring and semiconductor-equipment drives
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage distortion after a mounting blow carried through the roller set
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- brinelling from static overload or impact during handling
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 150 mm bore, oil-lubricated arrangements toward 3,300 r/min need positive flow and drain design; the 5900 g NN4930 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Wide (22/23) and light (10/49) executions at 150 mm bore share bore but not OD/width; check the full NN4900 series code before substituting, because housing and shoulder geometry will not interchange.
- Do not replace NN4930 with a deep-groove ball bearing on rating alone: line contact gives 380 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 NN rib arrangement is not interchangeable with another prefix on the same 150 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 210×60 mm envelope matches.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN4930 skids at 2,800 r/min and fails by smearing long before L10 fatigue.
- The 380/690 kN ratings, 70.5 kN Pu and 5900 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN4930 (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 NN4930?
NN4930 is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 150 mm bore, 210 mm OD and 60 mm width (5.906 × 8.268 × 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 380 kN, C0 690 kN, Pu 70.5 kN, grease limiting speed 2,800 r/min, oil 3,300 r/min, mass about 5900 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. NN4930 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. NN4930 is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN4930?
NN4930 has a cylindrical bore and mounts on a plain machined shaft seat; a K execution (1:12 taper) exists in the NN4900 series when preload must be set by drive-up on a tapered seat.
What do Fw and Ew mean for NN4930?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 168.5 mm, Ew 196.5159 mm. The nominal bore/OD remain 150/210 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,800 r/min grease / 3,300 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.