NF328 bearing: complete specifications & equivalents
The NF328 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 | 685 kN |
| Basic static load rating C0 | 745 kN |
| Fatigue load limit Pu | 72 kN |
| Limiting speed (mechanical) | 2300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 20700 g |
| Manufacturer designation | NTN NF328 |
| 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 & NF300-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 2.441 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 80 mm |
| Smallest bore in NF300-series | 20 mm |
| Largest outer diameter in NF300-series | 580 mm |
| Width range across NF300-series | 15–108 mm |
| Bore position in NF300-series (smallest first) | 22 of 32 |
| Bore above smallest NF300-series size | 120 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF328 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NF328 model number is decoded
The NTN order number NF328 denotes a 140×300×62 mm (5.512 × 11.811 × 2.441 in) cylindrical roller bearing in the NF300 family, a pressed sheet-steel cage. Digit by digit, NF328 reads as NF (one rib on each ring), 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. With C 685 kN and C0 745 kN (C0/C ≈ 1.09) the bearing is proportioned for heavy radial load; the NF design gives one-direction axial guidance via its single outer-ring rib. Selection arithmetic: Pu 72 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.09 (745/685 kN) shows the high-static-capacity proportioning of this 140 mm bore. Housing and shaft fillets must clear the ring chamfers of NF328; an oversized radius locks the ring on its face and tilts the 62 mm-wide seat.
Typical equipment & failure modes
Common applications
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- 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 140 mm bore, oil-lubricated arrangements toward 2,700 r/min need positive flow and drain design; the 20700 g NF328 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- 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 EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 685/745 kN pair here belongs to NF328 as printed, not to the bare size.
- If the shaft must be located both ways, do not use NF328 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NF328 skids at 2,300 r/min and fails by smearing long before L10 fatigue.
- The 685/745 kN ratings, 72 kN Pu and 20700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF328 (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 NF328?
NF328 is an NTN NF 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 685 kN, C0 745 kN, Pu 72 kN, grease limiting speed 2,300 r/min, oil 2,700 r/min, mass about 20700 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. NF328 is one integral rib on each ring — separable inner ring with single-direction axial guidance and a defined shaft position.
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. NF328 is supplied in the standard open execution shown in the table.
Can NF328 take axial load and locate a shaft?
the NF design gives one-direction axial guidance via its single outer-ring rib. 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 NF328?
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, Ew 260 mm. The nominal bore/OD remain 140/300 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,300 r/min grease / 2,700 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.