NU336 bearing: complete specifications & equivalents
The NU336 is a ISO 15 radial bearing sized 180 x 380 x 75 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 180 mm |
| Outer diameter D | 380 mm |
| Width B | 75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1000 kN |
| Basic static load rating C0 | 1150 kN |
| Fatigue load limit Pu | 103 kN |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 43200 g |
| Manufacturer designation | NTN NU336 |
| 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 & NU300-series range
| Bore d | 7.087 in |
|---|---|
| Outer diameter D | 14.961 in |
| Width B | 2.953 in |
| ISO bore code | 36 |
| Radial section height (D−d)/2 | 100 mm |
| Smallest bore in NU300-series | 17 mm |
| Largest outer diameter in NU300-series | 620 mm |
| Width range across NU300-series | 14–109 mm |
| Bore position in NU300-series (smallest first) | 27 of 34 |
| Bore above smallest NU300-series size | 163 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU336-ECM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 180×380×75 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 NU336 model number is decoded
For pure radial duty on a 180 mm shaft NTN supplies NU336: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 1,700 r/min on grease and 2,000 r/min on oil. Digit by digit, NU336 reads as NU (outer ring ribbed, inner ring ribless), ISO 15 series, and bore 180 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. the bare number is the standard-capacity open execution with the normal pressed-steel cage; quote the full NU336 designation when purchasing. Equivalent-load planning treats NU336 as a pure radial bearing: keep P below 1000 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. 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 NU336.
Typical equipment & failure modes
Common applications
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
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
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- At 180 mm bore, oil-lubricated arrangements toward 2,000 r/min need positive flow and drain design; the 43200 g NU336 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 380 mm race brinells and releases as vibration within hours.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 380 mm race brinells and releases as vibration within hours.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 380 mm race brinells and releases as vibration within hours.
- The 75 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 180 mm inner ring.
- The 1000/1150 kN ratings, 103 kN Pu and 43200 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU336 (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 NU336?
NU336 is an NTN NU single-row cylindrical roller bearing to ISO 15: 180 mm bore, 380 mm OD and 75 mm width (7.087 × 14.961 × 2.953 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1000 kN, C0 1150 kN, Pu 103 kN, grease limiting speed 1,700 r/min, oil 2,000 r/min, mass about 43200 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. NU336 is two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially.
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. NU336 is supplied in the standard open execution shown in the table.
Can NU336 take axial load and locate a shaft?
the NU design carries no axial load and floats axially on both sides. 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 NU336?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 232 mm, Ew 328 mm. The nominal bore/OD remain 180/380 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,700 r/min grease / 2,000 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.