NU1018 bearing: complete specifications & equivalents
The NU1018 is a ISO 15 radial bearing sized 90 x 140 x 24 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 90 mm |
| Outer diameter D | 140 mm |
| Width B | 24 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 98 kN |
| Basic static load rating C0 | 114 kN |
| Fatigue load limit Pu | 13.4 kN |
| Limiting speed (mechanical) | 5100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1310 g |
| Manufacturer designation | NTN NU1018 |
| 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 | 3.543 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 0.945 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 25 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) | 14 of 47 |
| Bore above smallest NU1000-series size | 65 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU1018-ML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 90×140×24 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 NU1018 model number is decoded
For pure radial duty on a 90 mm shaft NTN supplies NU1018: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 5,100 r/min on grease and 5,900 r/min on oil. On the NTN nameplate NU states which ring carries the ribs, which determines whether NU1018 floats or locates; the numeric remainder is the ISO 15 series and 90 mm bore reference, not a fit or clearance instruction. NTN prints the raceway diameters for this size — Fw 103 mm and Ew 127 mm — the envelope inside the 90/140 mm bore/OD where the rollers actually run. With the inner ring rotating, catalogue practice is a k5/m5 shaft seat and an H7/H6 housing; the outer ring must remain free to creep slightly axially in non-locating NU arrangements. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NU1018 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- large pump, turbine and compressor rotors
- rolling-mill auxiliary drive shafts
- crusher and vibrating-screen drive shafts
- marine gearbox and deck-machinery shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- 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
- Induction-heat the 90 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 140 mm raceway.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 98/114 kN pair here belongs to NU1018 as printed, not to the bare size.
- Wide (22/23) and light (10/49) executions at 90 mm bore share bore but not OD/width; check the full NU1000 series code before substituting, because housing and shoulder geometry will not interchange.
- Grease limiting speed 5,100 r/min and oil 5,900 r/min are different limits for NU1018: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The NU rib arrangement is not interchangeable with another prefix on the same 90 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 140×24 mm envelope matches.
- The 98/114 kN ratings, 13.4 kN Pu and 1310 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU1018 (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 NU1018?
NU1018 is an NTN NU single-row cylindrical roller bearing to ISO 15: 90 mm bore, 140 mm OD and 24 mm width (3.543 × 5.512 × 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 98 kN, C0 114 kN, Pu 13.4 kN, grease limiting speed 5,100 r/min, oil 5,900 r/min, mass about 1310 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. NU1018 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. NU1018 is supplied in the standard open execution shown in the table.
Can NU1018 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 NU1018?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 103 mm, Ew 127 mm. The nominal bore/OD remain 90/140 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 5,100 r/min grease / 5,900 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.