65390-65320-NTN bearing: complete specifications & equivalents
The 65390-65320-NTN is a ANSI ABMA 19.2 radial bearing sized 49.212 x 114.3 x 44.45 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 49.212 mm |
| Outer diameter D | 114.3 mm |
| Width B | 44.45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 206 kN |
| Basic static load rating C0 | 225 kN |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2230 g |
| Manufacturer designation | NTN 4T-65390/65320 |
| Standard | ANSI ABMA 19.2 |
| Catalog version | NTN 2203E 2026-09-25 |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN 2203E 2026-09-25) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN 2203E 2026-09-25); 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 & 4t-inch-series range
| Bore d | 1.937 in |
|---|---|
| Outer diameter D | 4.5 in |
| Width B | 1.75 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 32.5 mm |
| Smallest bore in 4t-inch-series | 12.7 mm |
| Largest outer diameter in 4t-inch-series | 260 mm |
| Width range across 4t-inch-series | 10.998–77.788 mm |
| Bore position in 4t-inch-series (smallest first) | 61 of 148 |
| Bore above smallest 4t-inch-series size | 36.512 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 65390-65320 | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per 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 65390-65320-NTN model number is decoded
NTN supplies this 1.937 in (49.212 mm) shaft position as 4T-65390/65320: cone 65390, cup 65320, profiled rollers and a pressed-steel cage, rated 206 kN basic dynamic and 225 kN static. The 4T prefix is NTN's tapered roller quality mark stamped on both parts; it is a brand mark, not a size code, so cross-references quote 65390/65320 without it. Grease relubrication at the 3,600 r/min limiting speed targets the cone-rib contact; sustaining 4,800 r/min needs an oil supply directed at the large roller ends. The printed 206/225 kN ratings belong to the assembled 65390+65320 pair; a sibling row using the same cone with a different cup carries its own rating row because the raceway track shifts with the cup. The rollers run with their large ends against the cone's guide rib; lubricant must reach that rib face of 4T-65390/65320, not only the raceway, or the pair smears on the first overloaded start.
Typical equipment & failure modes
Common applications
- construction-equipment pivot and wheel positions
- mining and quarry conveyor drive pulleys
- machine-tool headstocks on inch spindles
- pump and blower drive shafts with combined load
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- cup creep and housing fretting when the cup seat is cut too loose for the rotating load
- flaking on one cone only when a bent shaft loads the O/X pair unevenly
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 49.212 mm class are adjusted in pairs; verify end play against the axle or gearbox drawing and re-torque after bedding-in instead of trusting the first setting on 4T-65390/65320.
- The pure-numeric inch family at 49.212 mm bore (114.3×44.45 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 65390/65320 reference at purchase.
- Quote the full 65390/65320 pair at ordering: the 65390 cone also ships against sibling cups, and a cup from another reference changes the 44.45 mm assembled width and the rating.
- Replacing one half of an adjusted pair without resetting end play negates the 44.45 mm T logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Never drive the 114.3 mm cup home through the rollers: fitting force goes through the ring faces only, or brinell marks release as noise within the first running hours.
- The 206/225 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-65390/65320; internal geometry legitimately differs between inch-series makers, so re-verify ratings, adjustment and the exact cone/cup references before substituting another brand on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 4T-65390/65320?
4T-65390/65320 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 49.212 mm bore (1.937 in), 114.3 mm outside diameter and 44.45 mm assembled width T (4.5 × 1.75 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 206 kN, C0 225 kN, grease limiting speed 3,600 r/min, oil speed 4,800 r/min, mass about 2230 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-65390/65320 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 65390 cone or the 65320 cup can be replaced by an identical reference from NTN or another ABMA-dimensioned maker. Pairing the cone with a different cup reference is a different catalogue row: OD, assembled T and the 206/225 kN ratings change with the cup.
What is the difference between 4T-65390/65320 and a metric ISO 355 tapered bearing?
4T-65390/65320 follows the ABMA inch boundary plan with cone/cup references; ISO 355 bearings use metric dimension-series numbers (302, 322, …). Even where a metric size looks close to 49.212×114.3×44.45 mm, the envelopes and contact angles differ — the two systems are not drop-in interchangeable; check every boundary value before substituting.
What does the 4T prefix on 4T-65390/65320 mean?
4T is NTN's tapered roller bearing quality mark, stamped on cone and cup in the factory. It identifies NTN's 4T programme and is not a dimension or variant code, so interchange lists quote the bare 65390/65320 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-65390/65320 list two speeds, 3,600 and 4,800 r/min?
The lower figure, 3,600 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 4T-65390/65320 at 4,800 r/min because oil removes rib-contact heat better. Real limits still depend on pair adjustment, oil flow and cooling.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN 2203E 2026-09-25 on 2026-10-01. Read our editorial & correction policy.