NUP320 bearing: complete specifications & equivalents
The NUP320 is a ISO 15 radial bearing sized 100 x 215 x 47 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 47 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 330 kN |
| Basic static load rating C0 | 335 kN |
| Fatigue load limit Pu | 36 kN |
| Limiting speed (mechanical) | 3300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7320 g |
| Manufacturer designation | NTN NUP320 |
| 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 & NUP300-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.85 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 mm |
| Smallest bore in NUP300-series | 20 mm |
| Largest outer diameter in NUP300-series | 580 mm |
| Width range across NUP300-series | 15–108 mm |
| Bore position in NUP300-series (smallest first) | 17 of 32 |
| Bore above smallest NUP300-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP320-ECJ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 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 NUP320 model number is decoded
NUP320 belongs to the NTN cylindrical roller range in NTN Ball and Roller Bearings CAT.No.2203E: line-contact rollers between ground raceways for a 330 kN dynamic rating in the 100 mm bore. On the NTN nameplate NUP states which ring carries the ribs, which determines whether NUP320 floats or locates; the numeric remainder is the ISO 15 series and 100 mm bore reference, not a fit or clearance instruction. The 57.5 mm radial section ((215−100)/2) frames the roller complement; capacity per millimetre of bore is about 3.3 kN/mm before application factors. Mass 7320 g for the 100×215×47 mm NUP320 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. Confirm the loose L-shaped rib ring is fitted and seated, since it is what turns the NJ-type arrangement into the two-direction-locating NUP set on the 100 mm shaft.
Typical equipment & failure modes
Common applications
- rolling-mill auxiliary drive shafts
- crusher and vibrating-screen drive shafts
- marine gearbox and deck-machinery shafts
- large electric-motor and generator rotors
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
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Induction-heat the 100 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 215 mm raceway.
- Do not replace NUP320 with a deep-groove ball bearing on rating alone: line contact gives 330 kN radial capacity but the bearing only accepts small sustained axial guidance loads and misalignment tolerance is only 3–4 arc-minutes.
- Do not replace NUP320 with a deep-groove ball bearing on rating alone: line contact gives 330 kN radial capacity but the bearing only accepts small sustained axial guidance loads and misalignment tolerance is only 3–4 arc-minutes.
- Open NUP320 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 100 mm contact.
- The 57.5 mm section at 100 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 47 mm-wide cavity.
- The 330/335 kN ratings, 36 kN Pu and 7320 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP320 (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 NUP320?
NUP320 is an NTN NUP single-row cylindrical roller bearing to ISO 15: 100 mm bore, 215 mm OD and 47 mm width (3.937 × 8.465 × 1.85 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 330 kN, C0 335 kN, Pu 36 kN, grease limiting speed 3,300 r/min, oil 3,800 r/min, mass about 7320 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. NUP320 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. NUP320 is supplied in the standard open execution shown in the table.
Can NUP320 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 NUP320?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 129.5 mm, Ew 185.5 mm. The nominal bore/OD remain 100/215 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 3,300 r/min grease / 3,800 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.