NU1011 bearing: complete specifications & equivalents
The NU1011 is a ISO 15 radial bearing sized 55 x 90 x 18 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 90 mm |
| Width B | 18 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 42 kN |
| Basic static load rating C0 | 44 kN |
| Fatigue load limit Pu | 5.35 kN |
| Limiting speed (mechanical) | 8200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 435 g |
| Manufacturer designation | NTN NU1011 |
| 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 | 2.165 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.709 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 17.5 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) | 7 of 47 |
| Bore above smallest NU1000-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU1011-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 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 NU1011 model number is decoded
For pure radial duty on a 55 mm shaft NTN supplies NU1011: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 8,200 r/min on grease and 9,700 r/min on oil. The leading NU defines the rib arrangement (outer ring ribbed, inner ring ribless); the dimension-series digits and the two-digit bore code resolve to 55 mm, with 90 mm OD and 18 mm width from the ISO 15 general plan. the bare number is the standard-capacity open execution with the normal pressed-steel cage; quote the full NU1011 designation when purchasing. Thermal planning around the 8,200 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 9,700 r/min for continuously high-duty 55 mm positions. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NU1011 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
- machine-tool gearbox and spindle radial sets
- material-handling drum and wheel shafts
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage distortion after a mounting blow carried through the roller set
- 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
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- On this 55 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting NU1011.
- The 17.5 mm section at 55 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 18 mm-wide cavity.
- The NU rib arrangement is not interchangeable with another prefix on the same 55 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 90×18 mm envelope matches.
- If the shaft must be located both ways, do not use NU1011 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 18 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 55 mm inner ring.
- The 42/44 kN ratings, 5.35 kN Pu and 435 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU1011 (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 NU1011?
NU1011 is an NTN NU single-row cylindrical roller bearing to ISO 15: 55 mm bore, 90 mm OD and 18 mm width (2.165 × 3.543 × 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 42 kN, C0 44 kN, Pu 5.35 kN, grease limiting speed 8,200 r/min, oil 9,700 r/min, mass about 435 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. NU1011 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. NU1011 is supplied in the standard open execution shown in the table.
Can NU1011 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 NU1011?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 64.5 mm, Ew 80.5 mm. The nominal bore/OD remain 55/90 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 8,200 r/min grease / 9,700 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.