NU352 bearing: complete specifications & equivalents
The NU352 is a ISO 15 radial bearing sized 260 x 540 x 102 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 260 mm |
| Outer diameter D | 540 mm |
| Width B | 102 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1790 kN |
| Basic static load rating C0 | 2230 kN |
| Fatigue load limit Pu | 180 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 114000 g |
| Manufacturer designation | NTN NU352 |
| 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 | 10.236 in |
|---|---|
| Outer diameter D | 21.26 in |
| Width B | 4.016 in |
| ISO bore code | 52 |
| Radial section height (D−d)/2 | 140 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) | 32 of 34 |
| Bore above smallest NU300-series size | 243 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU352-ECMA | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 260×540×102 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 NU352 model number is decoded
NU352 belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E: line-contact rollers between ground raceways for a 1790 kN dynamic rating in the 260 mm bore. Digit by digit, NU352 reads as NU (outer ring ribbed, inner ring ribless), ISO 15 series, and bore 260 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 NU352 designation when purchasing. The 260 mm (10.236 in) bore and 540 mm (21.26 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 102 mm-wide ring. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NU352 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
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- electrical pitting on VFD-driven motor shafts without grounding protection
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- At 260 mm bore, oil-lubricated arrangements toward 1,400 r/min need positive flow and drain design; the 114000 g NU352 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The NU rib arrangement is not interchangeable with another prefix on the same 260 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 540×102 mm envelope matches.
- The 102 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 260 mm inner ring.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NU352 skids at 1,200 r/min and fails by smearing long before L10 fatigue.
- The 102 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 260 mm inner ring.
- The 1790/2230 kN ratings, 180 kN Pu and 114000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU352 (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 NU352?
NU352 is an NTN NU single-row cylindrical roller bearing to ISO 15: 260 mm bore, 540 mm OD and 102 mm width (10.236 × 21.26 × 4.016 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1790 kN, C0 2230 kN, Pu 180 kN, grease limiting speed 1,200 r/min, oil 1,400 r/min, mass about 114000 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. NU352 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. NU352 is supplied in the standard open execution shown in the table.
Can NU352 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 NU352?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 336 mm, Ew 464 mm. The nominal bore/OD remain 260/540 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,200 r/min grease / 1,400 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.