6580-6535-NTN bearing: complete specifications & equivalents
The 6580-6535-NTN is a ANSI ABMA 19.2 radial bearing sized 88.9 x 161.925 x 53.975 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 88.9 mm |
| Outer diameter D | 161.925 mm |
| Width B | 53.975 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 340 kN |
| Basic static load rating C0 | 460 kN |
| Limiting speed (mechanical) | 2300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 4720 g |
| Manufacturer designation | NTN 4T-6580/6535 |
| 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 | 3.5 in |
|---|---|
| Outer diameter D | 6.375 in |
| Width B | 2.125 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 36.5 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) | 106 of 148 |
| Bore above smallest 4t-inch-series size | 76.2 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6580-6535 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 88.9×161.925×53.975 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 6580-6535-NTN model number is decoded
4T-6580/6535 is an NTN inch-series single-row tapered roller bearing: a separable cone-and-cup pair on the ABMA inch boundary plan, 88.9×161.925×53.975 mm (assembled width T), for a shaft of about 88.9 mm (3.5 in). Unlike ISO 355 metric numbers, this ABMA code does not encode the bore arithmetically: 6580 identifies the cone of 88.9 mm (3.5 in) bore by catalogue lookup, and 6535 fixes the 161.925 mm OD. Speed planning uses both catalogue columns: grease 2,300 r/min is the mechanical ceiling for 4T-6580/6535, oil 3,000 r/min with circulating oil — a 700 r/min margin at this size. Housing fitment sequence for 4T-6580/6535: press the 6535 cup square into the 161.925 mm seat first, then bring the 6580 cone (on its 88.9 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. Mount the 88.9 mm cone with an induction heater (max 120 °C) and press the 161.925 mm cup with a sleeve; driving either ring through the rollers brinells the raceways.
Typical equipment & failure modes
Common applications
- heavy truck and bus drive-axle differentials
- plant gearboxes on inch-dimensioned shaft lines
- large conveyor head pulleys in bulk-handling plant
- paper-machine and calender roll supports
Known failure patterns
- cone-rib and roller large-end smearing when the adjusted pair runs with preload but starved lubricant film
- flaking on one cone only when a bent shaft loads the O/X pair unevenly
- cup creep and housing fretting when the cup seat is cut too loose for the rotating load
- cage damage from a mounting blow transmitted through the roller complement
- edge loading when shaft deflection exceeds the few arc-minutes an adjusted pair tolerates
Selection pitfalls — read before you substitute
- Mount the 88.9 mm cone by induction heating (max 120 °C) and the 161.925 mm cup with a press sleeve; at 4720 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 88.9 mm bore (161.925×53.975 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 6580/6535 reference at purchase.
- ABMA makes the 88.9×161.925 mm envelope interchangeable, not the ratings: NTN prints 340/460 kN for this execution and another make of the same number can differ in roller complement.
- ABMA makes the 88.9×161.925 mm envelope interchangeable, not the ratings: NTN prints 340/460 kN for this execution and another make of the same number can differ in roller complement.
- Inch and metric bores collide on paper — 88.9 mm is 3.5 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- The 340/460 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-6580/6535; 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-6580/6535?
4T-6580/6535 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 88.9 mm bore (3.5 in), 161.925 mm outside diameter and 53.975 mm assembled width T (6.375 × 2.125 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 340 kN, C0 460 kN, grease limiting speed 2,300 r/min, oil speed 3,000 r/min, mass about 4720 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-6580/6535 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 6580 cone or the 6535 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 340/460 kN ratings change with the cup.
What is the difference between 4T-6580/6535 and a metric ISO 355 tapered bearing?
4T-6580/6535 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 88.9×161.925×53.975 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-6580/6535 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 6580/6535 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-6580/6535 list two speeds, 2,300 and 3,000 r/min?
The lower figure, 2,300 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-6580/6535 at 3,000 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.