N408 bearing: complete specifications & equivalents
The N408 is a ISO 15 radial bearing sized 40 x 110 x 27 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 110 mm |
| Width B | 27 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 106 kN |
| Basic static load rating C0 | 89 kN |
| Fatigue load limit Pu | 10.9 kN |
| Limiting speed (mechanical) | 5700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1270 g |
| Manufacturer designation | NTN N408 |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 1.063 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 35 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) | 4 of 12 |
| Bore above smallest N400-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N408 | 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 N408 model number is decoded
The NTN order number N408 denotes a 40×110×27 mm (1.575 × 4.331 × 1.063 in) cylindrical roller bearing in the N400 family, a pressed sheet-steel cage. On the NTN nameplate N states which ring carries the ribs, which determines whether N408 floats or locates; the numeric remainder is the ISO 15 series and 40 mm bore reference, not a fit or clearance instruction. Line contact between rollers and raceways gives N408 high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. Selection arithmetic: Pu 10.9 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 0.84 (89/106 kN) shows the high-static-capacity proportioning of this 40 mm bore. On N arrangements confirm which ring is separable before heating: forcing the ribbed ring off over the roller complement damages the cage and rib faces.
Typical equipment & failure modes
Common applications
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
- machine-tool gearbox and spindle radial sets
- material-handling drum and wheel 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
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- electrical pitting on VFD-driven motor shafts without grounding protection
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- On this 40 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 N408.
- Grease limiting speed 5,700 r/min and oil 6,700 r/min are different limits for N408: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 27 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 40 mm inner ring.
- The 35.0 mm section at 40 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 27 mm-wide cavity.
- Wide (22/23) and light (10/49) executions at 40 mm bore share bore but not OD/width; check the full N400 series code before substituting, because housing and shoulder geometry will not interchange.
- The 106/89 kN ratings, 10.9 kN Pu and 1270 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N408 (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 N408?
N408 is an NTN N single-row cylindrical roller bearing to ISO 15: 40 mm bore, 110 mm OD and 27 mm width (1.575 × 4.331 × 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 106 kN, C0 89 kN, Pu 10.9 kN, grease limiting speed 5,700 r/min, oil 6,700 r/min, mass about 1270 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. N408 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. N408 is supplied in the standard open execution shown in the table.
Can N408 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 N408?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 58 mm, Ew 92 mm. The nominal bore/OD remain 40/110 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 5,700 r/min grease / 6,700 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.