N406 bearing: complete specifications & equivalents
The N406 is a ISO 15 radial bearing sized 30 x 90 x 23 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 30 mm |
| Outer diameter D | 90 mm |
| Width B | 23 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 69.5 kN |
| Basic static load rating C0 | 55 kN |
| Fatigue load limit Pu | 6.7 kN |
| Limiting speed (mechanical) | 7300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 732 g |
| Manufacturer designation | NTN N406 |
| 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 & N400-series range
| Bore d | 1.181 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.906 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 30 mm |
| Smallest bore in N400-series | 25 mm |
| Largest outer diameter in N400-series | 200 mm |
| Width range across N400-series | 21–48 mm |
| Bore position in N400-series (smallest first) | 2 of 12 |
| Bore above smallest N400-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N406 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 N406 model number is decoded
N406 is the heavy (04) section of the NTN N400 dimension series for a 30 mm shaft — 69.5 kN of basic dynamic capacity in a 732 g, open bearing. The leading N defines the rib arrangement (inner ring ribbed, outer ring ribless); the dimension-series digits and the two-digit bore code resolve to 30 mm, with 90 mm OD and 23 mm width from the ISO 15 general plan. The 23 mm width and 30.0 mm section put the N400 series in the heavy (04) section; wide 22/23 variants at the same bore change OD, width and heat generation and are not drop-in swaps. Speed ratio check: limiting 7,300 r/min is .86 of the 8,500 r/min oil value for N406; grease-churn heating closes that gap as fill quantity rises. Heat the inner ring to max 120 °C for the 30 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
Typical equipment & failure modes
Common applications
- material-handling drum and wheel shafts
- papermaking and printing auxiliary drives
- fan and blower rotor positions
- industrial gearbox input and output shafts
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- rolling-contact fatigue after the catalogue L10 life is exceeded
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- On this 30 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting N406.
- Do not replace N406 with a deep-groove ball bearing on rating alone: line contact gives 69.5 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Open N406 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 30 mm contact.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N406 skids at 7,300 r/min and fails by smearing long before L10 fatigue.
- Open N406 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 30 mm contact.
- The 69.5/55 kN ratings, 6.7 kN Pu and 732 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N406 (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 N406?
N406 is an NTN N single-row cylindrical roller bearing to ISO 15: 30 mm bore, 90 mm OD and 23 mm width (1.181 × 3.543 × 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 69.5 kN, C0 55 kN, Pu 6.7 kN, grease limiting speed 7,300 r/min, oil 8,500 r/min, mass about 732 g. It is open, with a pressed sheet-steel cage.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
The prefix states the rib arrangement: NU has two outer-ring ribs and a ribless inner ring (float, no axial load); NJ adds ribs for one-direction location; NUP adds a loose L-ring to locate both directions; N has two inner-ring ribs and a separable outer ring; NF has one rib per ring for one-direction guidance. N406 is two integral ribs on the inner ring and a ribless separable outer ring — equivalent float behaviour with the separable ring on the housing side.
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. N406 is supplied in the standard open execution shown in the table.
Can N406 take axial load and locate a shaft?
the N design is non-locating like NU but floats with the separable outer ring in the housing. Provide axial location with an adjacent locating bearing (angular-contact, deep-groove or a paired NJ/NUP set).
What do Fw and Ew mean for N406?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 45 mm, Ew 73 mm. The nominal bore/OD remain 30/90 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 7,300 r/min grease / 8,500 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.