N340 bearing: complete specifications & equivalents
The N340 is a ISO 15 radial bearing sized 200 x 420 x 80 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 200 mm |
| Outer diameter D | 420 mm |
| Width B | 80 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1080 kN |
| Basic static load rating C0 | 1270 kN |
| Fatigue load limit Pu | 111 kN |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 54500 g |
| Manufacturer designation | NTN N340 |
| 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 & N300-series range
| Bore d | 7.874 in |
|---|---|
| Outer diameter D | 16.535 in |
| Width B | 3.15 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 110 mm |
| Smallest bore in N300-series | 17 mm |
| Largest outer diameter in N300-series | 580 mm |
| Width range across N300-series | 14–108 mm |
| Bore position in N300-series (smallest first) | 29 of 33 |
| Bore above smallest N300-series size | 183 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N340 | 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 N340 model number is decoded
N340 is an NTN N cylindrical roller bearing: two integral ribs on the inner ring and a ribless separable outer ring — equivalent float behaviour with the separable ring on the housing side, inside the 200×420×80 mm ISO 15 envelope. Numbering ties N340 to its envelope: type code N, series N300, 200 mm bore; the 420×80 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. With C 1080 kN and C0 1270 kN (C0/C ≈ 1.18) the bearing is proportioned for heavy radial load; the N design is non-locating like NU but floats with the separable outer ring in the housing. Rating life at 1080 kN C assumes clean oil and adequate film; the 111 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of N340.
Typical equipment & failure modes
Common applications
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- 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
- false brinelling on standby machines exposed to external vibration
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 200 mm bore, oil-lubricated arrangements toward 1,800 r/min need positive flow and drain design; the 54500 g N340 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The N rib arrangement is not interchangeable with another prefix on the same 200 mm seat: inner ring ribbed, outer ring ribless. Swapping NU for NJ changes axial location behaviour even though the 420×80 mm envelope matches.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N340 skids at 1,500 r/min and fails by smearing long before L10 fatigue.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N340 skids at 1,500 r/min and fails by smearing long before L10 fatigue.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N340 skids at 1,500 r/min and fails by smearing long before L10 fatigue.
- The 1080/1270 kN ratings, 111 kN Pu and 54500 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N340 (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 N340?
N340 is an NTN N single-row cylindrical roller bearing to ISO 15: 200 mm bore, 420 mm OD and 80 mm width (7.874 × 16.535 × 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1080 kN, C0 1270 kN, Pu 111 kN, grease limiting speed 1,500 r/min, oil 1,800 r/min, mass about 54500 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. N340 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. N340 is supplied in the standard open execution shown in the table.
Can N340 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 N340?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 260 mm, Ew 360 mm. The nominal bore/OD remain 200/420 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,500 r/min grease / 1,800 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.