NJ405 bearing: complete specifications & equivalents
The NJ405 is a ISO 15 radial bearing sized 25 x 80 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 25 mm |
| Outer diameter D | 80 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 51.5 kN |
| Basic static load rating C0 | 40 kN |
| Fatigue load limit Pu | 4.85 kN |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 536 g |
| Manufacturer designation | NTN NJ405 |
| 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 & NJ400-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.827 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in NJ400-series | 25 mm |
| Largest outer diameter in NJ400-series | 280 mm |
| Width range across NJ400-series | 21–65 mm |
| Bore position in NJ400-series (smallest first) | 1 of 13 |
| Bore above smallest NJ400-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ405 | 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 NJ405 model number is decoded
For pure radial duty on a 25 mm shaft NTN supplies NJ405: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 8,500 r/min on grease and 10,000 r/min on oil. The leading NJ defines the rib arrangement (inner ring two ribs + one outer rib); the dimension-series digits and the two-digit bore code resolve to 25 mm, with 80 mm OD and 21 mm width from the ISO 15 general plan. With C 51.5 kN and C0 40 kN (C0/C ≈ 0.78) the bearing is proportioned for heavy radial load; the NJ design accepts axial load in one direction and provides one-way shaft location. Thermal planning around the 8,500 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 10,000 r/min for continuously high-duty 25 mm positions. The NJ design locates in one direction only: for two-direction location fit the matching loose rib ring (NUP execution) or pair the bearings back to back on the 25 mm shaft.
Typical equipment & failure modes
Common applications
- two-wheeler and small-engine transmission shafts
- small pump and compressor rotor shafts
- appliance and office-machine drives
- agricultural PTO and implement gear shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- rolling-contact fatigue after the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- Small 25 mm-bore cylindrical rollers are skid-sensitive: ensure the radial load exceeds the minimum-load floor at operating speed, or the NJ405 rollers smear even with correct grease.
- If the shaft must be located both ways, do not use NJ405 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Do not replace NJ405 with a deep-groove ball bearing on rating alone: line contact gives 51.5 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The NJ rib arrangement is not interchangeable with another prefix on the same 25 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 80×21 mm envelope matches.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ405 skids at 8,500 r/min and fails by smearing long before L10 fatigue.
- The 51.5/40 kN ratings, 4.85 kN Pu and 536 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ405 (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 NJ405?
NJ405 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 25 mm bore, 80 mm OD and 21 mm width (0.984 × 3.15 × 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 51.5 kN, C0 40 kN, Pu 4.85 kN, grease limiting speed 8,500 r/min, oil 10,000 r/min, mass about 536 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. NJ405 is two integral ribs on the inner ring and one rib on the outer ring — it locates the shaft in one axial direction.
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. NJ405 is supplied in the standard open execution shown in the table.
Can NJ405 take axial load and locate a shaft?
the NJ design accepts axial load in one direction and provides one-way shaft location. For two-direction location use an NUP execution or an NJ pair with loose rib rings.
What do Fw and Ew mean for NJ405?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 38.8 mm, Ew 62.8 mm. The nominal bore/OD remain 25/80 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 8,500 r/min grease / 10,000 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.