NUP2304EA bearing: complete specifications & equivalents
The NUP2304EA is a ISO 15 radial bearing sized 20 x 52 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 20 mm |
| Outer diameter D | 52 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 49.5 kN |
| Basic static load rating C0 | 39 kN |
| Fatigue load limit Pu | 4.75 kN |
| Limiting speed (mechanical) | 12000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 212 g |
| Manufacturer designation | NTN NUP2304EA |
| 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 & NUP2300-series range
| Bore d | 0.787 in |
|---|---|
| Outer diameter D | 2.047 in |
| Width B | 0.827 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 16 mm |
| Smallest bore in NUP2300-series | 20 mm |
| Largest outer diameter in NUP2300-series | 580 mm |
| Width range across NUP2300-series | 21–175 mm |
| Bore position in NUP2300-series (smallest first) | 1 of 31 |
| Bore above smallest NUP2300-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP2304EA | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 NUP2304EA model number is decoded
NUP2304EA belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E, under the ＊ ULTAGE new-generation specification: line-contact rollers between ground raceways for a 49.5 kN dynamic rating in the 20 mm bore. Digit by digit, NUP2304EA reads as NUP (inner ring two ribs + loose L-ring), ISO 15 series, and bore 20 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. With C 49.5 kN and C0 39 kN (C0/C ≈ 0.79) the bearing is proportioned for heavy radial load; the NUP design provides two-direction axial location via its loose rib ring, for light/moderate thrust guidance. Rating life at 49.5 kN C assumes clean oil and adequate film; the 4.75 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. Housing and shaft fillets must clear the ring chamfers of NUP2304EA; an oversized radius locks the ring on its face and tilts the 21 mm-wide seat.
Typical equipment & failure modes
Common applications
- agricultural PTO and implement gear shafts
- small conveyor and fan rotor positions
- small electric-motor armature shafts
- light gearbox layshaft and pinion positions
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
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- brinelling from static overload or impact during handling
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- Small 20 mm-bore cylindrical rollers are skid-sensitive: ensure the radial load exceeds the minimum-load floor at operating speed, or the NUP2304EA rollers smear even with correct grease.
- The NUP rib arrangement is not interchangeable with another prefix on the same 20 mm seat: inner ring two ribs + loose L-ring. Swapping NU for NJ changes axial location behaviour even though the 52×21 mm envelope matches.
- If the shaft must be located both ways, do not use NUP2304EA alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 21 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 20 mm inner ring.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NUP2304EA skids at 12,000 r/min and fails by smearing long before L10 fatigue.
- The 49.5/39 kN ratings, 4.75 kN Pu and 212 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP2304EA (EA pressed-steel-cage 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 NUP2304EA?
NUP2304EA is an NTN NUP single-row cylindrical roller bearing to ISO 15: 20 mm bore, 52 mm OD and 21 mm width (0.787 × 2.047 × 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49.5 kN, C0 39 kN, Pu 4.75 kN, grease limiting speed 12,000 r/min, oil 16,800 r/min, mass about 212 g. It is open, with the EA high-capacity 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. NUP2304EA is the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions.
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. This page's bearing carries the EA pressed-steel-cage execution.
Can NUP2304EA take axial load and locate a shaft?
the NUP design provides two-direction axial location via its loose rib ring, for light/moderate thrust guidance. The loose rib ring still only suits light/short-duration axial guidance; heavy thrust belongs to a dedicated thrust bearing.
What do Fw and Ew mean for NUP2304EA?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 27.5 mm, Ew 45.5 mm. The nominal bore/OD remain 20/52 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 12,000 r/min grease / 16,800 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.