NU1052 bearing: complete specifications & equivalents
The NU1052 is a ISO 15 radial bearing sized 260 x 400 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 | 260 mm |
| Outer diameter D | 400 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 715 kN |
| Basic static load rating C0 | 1000 kN |
| Fatigue load limit Pu | 85 kN |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 28700 g |
| Manufacturer designation | NTN NU1052 |
| 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 & NU1000-series range
| Bore d | 10.236 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 2.559 in |
| ISO bore code | 52 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NU1000-series | 25 mm |
| Largest outer diameter in NU1000-series | 1090 mm |
| Width range across NU1000-series | 12–150 mm |
| Bore position in NU1000-series (smallest first) | 30 of 47 |
| Bore above smallest NU1000-series size | 235 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU1052-ML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 260×400×65 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 NU1052 model number is decoded
NU1052 is the extra-light (10/49) section of the NTN NU1000 dimension series for a 260 mm shaft — 715 kN of basic dynamic capacity in a 28700 g, open bearing. Reading the code: NU for the non-locating separable-inner-ring type, then the ISO 15 diameter/width series and the bore code — ×5 = 260 mm (00–03 use the 10/12/15/17 exception table). NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of NU1052. Mass 28700 g for the 260×400×65 mm NU1052 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. On NU arrangements confirm which ring is separable before heating: forcing the ribbed ring off over the roller complement damages the cage and rib faces.
Typical equipment & failure modes
Common applications
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
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
- roller-end and raceway scoring from inadequate oil flow under heavy radial 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 260 mm bore, oil-lubricated arrangements toward 1,900 r/min need positive flow and drain design; the 28700 g NU1052 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 400×65 mm envelope matches.
- Open NU1052 units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 260 mm contact.
- The 65 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.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 400 mm race brinells and releases as vibration within hours.
- The 715/1000 kN ratings, 85 kN Pu and 28700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU1052 (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 NU1052?
NU1052 is an NTN NU single-row cylindrical roller bearing to ISO 15: 260 mm bore, 400 mm OD and 65 mm width (10.236 × 15.748 × 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 715 kN, C0 1000 kN, Pu 85 kN, grease limiting speed 1,600 r/min, oil 1,900 r/min, mass about 28700 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. NU1052 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. NU1052 is supplied in the standard open execution shown in the table.
Can NU1052 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 NU1052?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 296 mm, Ew 364 mm. The nominal bore/OD remain 260/400 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,600 r/min grease / 1,900 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.