NF320 bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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 NF320 model number is decoded

For pure radial duty on a 100 mm shaft NTN supplies NF320: one integral rib on each ring; the open execution is rated 3,300 r/min on grease and 3,800 r/min on oil. Numbering ties NF320 to its envelope: type code NF, series NF300, 100 mm bore; the 215×47 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. Line contact between rollers and raceways gives NF320 high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. Rating life at 330 kN C assumes clean oil and adequate film; the 36 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NF320 non-locating position preloads the bearing when the shaft grows.

Typical equipment & failure modes

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 NF320 with a deep-groove ball bearing on rating alone: line contact gives 330 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
• Grease limiting speed 3,300 r/min and oil 3,800 r/min are different limits for NF320: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
• Do not replace NF320 with a deep-groove ball bearing on rating alone: line contact gives 330 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
• Wide (22/23) and light (10/49) executions at 100 mm bore share bore but not OD/width; check the full NF300 series code before substituting, because housing and shoulder geometry will not interchange.
• The 330/335 kN ratings, 36 kN Pu and 7320 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF320 (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.