NU328E bearing: complete specifications & equivalents
The NU328E is a ISO 15 radial bearing sized 140 x 300 x 62 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 140 mm |
| Outer diameter D | 300 mm |
| Width B | 62 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 735 kN |
| Basic static load rating C0 | 795 kN |
| Fatigue load limit Pu | 76.5 kN |
| Limiting speed (mechanical) | 2100 rpm |
| Operating temperature | -40 to +120 °C |
| Manufacturer designation | NTN NU328E |
| 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 & NU300-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 2.441 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 80 mm |
| Smallest bore in NU300-series | 17 mm |
| Largest outer diameter in NU300-series | 620 mm |
| Width range across NU300-series | 14–109 mm |
| Bore position in NU300-series (smallest first) | 23 of 34 |
| Bore above smallest NU300-series size | 123 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU328E | 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 NU328E model number is decoded
NU328E is the standard section of the NTN NU300 dimension series for a 140 mm shaft — 735 kN of basic dynamic capacity in a open bearing. Digit by digit, NU328E reads as NU (outer ring ribbed, inner ring ribless), ISO 15 series, and bore 140 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. the trailing E marks NTN high-capacity internal design at this larger bore, with the pressed-steel cage execution; quote the full NU328E designation when purchasing. 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. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NU328E non-locating position preloads the bearing when the shaft grows.
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
- fretting corrosion on a loose rotating shaft seat
- rolling-contact fatigue after the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- At 140 mm bore, oil-lubricated arrangements toward 2,400 r/min need positive flow and drain design; the NU328E 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 735/795 kN pair here belongs to NU328E as printed, not to the bare size.
- The NU rib arrangement is not interchangeable with another prefix on the same 140 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 300×62 mm envelope matches.
- If the shaft must be located both ways, do not use NU328E alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 62 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 140 mm inner ring.
- The 735/795 kN ratings, 76.5 kN Pu are NTN Ball and Roller Bearings CAT.No.2203E values for NU328E (E high-capacity 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 NU328E?
NU328E is an NTN NU single-row cylindrical roller bearing to ISO 15: 140 mm bore, 300 mm OD and 62 mm width (5.512 × 11.811 × 2.441 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 735 kN, C0 795 kN, Pu 76.5 kN, grease limiting speed 2,100 r/min, oil 2,400 r/min. It is open, with the high-capacity pressed-steel cage of the E execution.
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. NU328E 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. NU328E is supplied in the standard open execution shown in the table.
Can NU328E 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 NU328E?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 180 mm. The nominal bore/OD remain 140/300 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,100 r/min grease / 2,400 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.