N330 bearing: complete specifications & equivalents
The N330 is a ISO 15 radial bearing sized 150 x 320 x 65 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 | 320 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 735 kN |
| Basic static load rating C0 | 805 kN |
| Fatigue load limit Pu | 76 kN |
| Limiting speed (mechanical) | 2100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 24700 g |
| Manufacturer designation | NTN N330 |
| 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 | 5.906 in |
|---|---|
| Outer diameter D | 12.598 in |
| Width B | 2.559 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 85 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) | 24 of 33 |
| Bore above smallest N300-series size | 133 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N330 | 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 N330 model number is decoded
For pure radial duty on a 150 mm shaft NTN supplies N330: two integral ribs on the inner ring and a ribless separable outer ring; the open execution is rated 2,100 r/min on grease and 2,500 r/min on oil. Digit by digit, N330 reads as N (inner ring ribbed, outer ring ribless), 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. At 2,500 r/min with oil versus 2,100 r/min with grease (a 400 r/min band), lubrication choice for N330 is a thermal decision, not just a sealing one. The 150 mm (5.906 in) bore and 320 mm (12.598 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 65 mm-wide ring. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a N330 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
- heavy press and large gearbox main 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
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- brinelling from static overload or impact during handling
Selection pitfalls — read before you substitute
- At 150 mm bore, oil-lubricated arrangements toward 2,500 r/min need positive flow and drain design; the 24700 g N330 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 320 mm race brinells and releases as vibration within hours.
- The 85.0 mm section at 150 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 65 mm-wide cavity.
- If the shaft must be located both ways, do not use N330 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Grease limiting speed 2,100 r/min and oil 2,500 r/min are different limits for N330: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 735/805 kN ratings, 76 kN Pu and 24700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N330 (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 N330?
N330 is an NTN N single-row cylindrical roller bearing to ISO 15: 150 mm bore, 320 mm OD and 65 mm width (5.906 × 12.598 × 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 735 kN, C0 805 kN, Pu 76 kN, grease limiting speed 2,100 r/min, oil 2,500 r/min, mass about 24700 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. N330 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. N330 is supplied in the standard open execution shown in the table.
Can N330 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 N330?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 193 mm, Ew 277 mm. The nominal bore/OD remain 150/320 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,100 r/min grease / 2,500 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.