NU1024 bearing: complete specifications & equivalents
The NU1024 is a ISO 15 radial bearing sized 120 x 180 x 28 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 180 mm |
| Width B | 28 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 154 kN |
| Basic static load rating C0 | 191 kN |
| Fatigue load limit Pu | 20.6 kN |
| Limiting speed (mechanical) | 3800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2400 g |
| Manufacturer designation | NTN NU1024 |
| 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 | 4.724 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 1.102 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 30 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) | 19 of 47 |
| Bore above smallest NU1000-series size | 95 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU1024-ML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 120×180×28 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 NU1024 model number is decoded
NU1024 is the extra-light (10/49) section of the NTN NU1000 dimension series for a 120 mm shaft — 154 kN of basic dynamic capacity in a 2400 g, open bearing. 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 120 mm, with 180 mm OD and 28 mm width from the ISO 15 general plan. With C 154 kN and C0 191 kN (C0/C ≈ 1.24) the bearing is proportioned for heavy radial load; the NU design carries no axial load and floats axially on both sides. With the inner ring rotating, catalogue practice is a m6/n6 shaft seat and an H7/H6 housing; the outer ring must remain free to creep slightly axially in non-locating NU arrangements. Heat the inner ring to max 120 °C for the 120 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
Typical equipment & failure modes
Common applications
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive shafts
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- 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
- rolling-contact fatigue after the catalogue L10 life is exceeded
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- At 120 mm bore, oil-lubricated arrangements toward 4,400 r/min need positive flow and drain design; the 2400 g NU1024 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 154/191 kN pair here belongs to NU1024 as printed, not to the bare size.
- Do not replace NU1024 with a deep-groove ball bearing on rating alone: line contact gives 154 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The NU rib arrangement is not interchangeable with another prefix on the same 120 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 180×28 mm envelope matches.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NU1024 skids at 3,800 r/min and fails by smearing long before L10 fatigue.
- The 154/191 kN ratings, 20.6 kN Pu and 2400 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU1024 (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 NU1024?
NU1024 is an NTN NU single-row cylindrical roller bearing to ISO 15: 120 mm bore, 180 mm OD and 28 mm width (4.724 × 7.087 × 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 154 kN, C0 191 kN, Pu 20.6 kN, grease limiting speed 3,800 r/min, oil 4,400 r/min, mass about 2400 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. NU1024 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. NU1024 is supplied in the standard open execution shown in the table.
Can NU1024 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 NU1024?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 135 mm, Ew 165 mm. The nominal bore/OD remain 120/180 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 3,800 r/min grease / 4,400 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.