2580-2523 bearing: complete specifications & equivalents
The 2580-2523 is a ANSI ABMA 19.2 radial bearing sized 31.75 x 69.85 x 23.812 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 31.75 mm |
| Outer diameter D | 69.85 mm |
| Width B | 23.812 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 76.5 kN |
| Basic static load rating C0 | 81.5 kN |
| Limiting speed (mechanical) | 5700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 455 g |
| Manufacturer designation | NTN 4T-2580/2523 |
| 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 | 1.25 in |
|---|---|
| Outer diameter D | 2.75 in |
| Width B | 0.937 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 19 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) | 32 of 148 |
| Bore above smallest 4t-inch-series size | 19.05 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 2580-2520 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN cone 4T-2580 paired with a different cup (2520): cone interchangeable, cup differs — OD, assembled width T and ratings follow the cup. Verify the full cone/cup reference 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 2580-2523 model number is decoded
4T-2580/2523 is an NTN inch-series single-row tapered roller bearing: a separable cone-and-cup pair on the ABMA inch boundary plan, 31.75×69.85×23.812 mm (assembled width T), for a shaft of about 31.75 mm (1.25 in). Reading the designation: 4T-2580/2523 follows the ABMA inch convention — the number before the slash is the cone (inner ring with roller set and cage), the number after the slash is the cup (outer ring), and the pure-numeric inch family lettering ties the pair to its boundary plan. Selection: C 76.5 kN against C0 81.5 kN gives a C0/C ratio of 1.07 for the 31.75 mm bore; the pair is counted as one adjusted unit when checking L10 at the equivalent combined load. Housing fitment sequence for 4T-2580/2523: press the 2523 cup square into the 69.85 mm seat first, then bring the 2580 cone (on its 31.75 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. With a rotating shaft a k5/m5 cone seat and an easy-push cup seat are typical practice for 4T-2580/2523; reverse the fit logic when the cup rotates.
Typical equipment & failure modes
Common applications
- industrial gearboxes built to inch shafting
- construction-equipment pivot and wheel positions
- mining and quarry conveyor drive pulleys
- machine-tool headstocks on inch spindles
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 fatigue when the pair runs continuously near the grease limiting speed without oil cooling
- edge loading when shaft deflection exceeds the few arc-minutes an adjusted pair tolerates
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 31.75 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-2580/2523.
- The pure-numeric inch family at 31.75 mm bore (69.85×23.812 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 2580/2523 reference at purchase.
- Fit selection follows the rotating ring: a rotating cone on a 31.75 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Replacing one half of an adjusted pair without resetting end play negates the 23.812 mm T logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Shaft and housing fillets must clear the ring chamfers of 2580 and 2523; use undercut shoulders so the rings seat on the face, not on a radius.
- The 76.5/81.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-2580/2523; 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-2580/2523?
4T-2580/2523 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 31.75 mm bore (1.25 in), 69.85 mm outside diameter and 23.812 mm assembled width T (2.75 × 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 76.5 kN, C0 81.5 kN, grease limiting speed 5,700 r/min, oil speed 7,600 r/min, mass about 455 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-2580/2523 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 2580 cone or the 2523 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 76.5/81.5 kN ratings change with the cup.
What is the difference between 4T-2580/2523 and a metric ISO 355 tapered bearing?
4T-2580/2523 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 31.75×69.85×23.812 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-2580/2523 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 2580/2523 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-2580/2523 list two speeds, 5,700 and 7,600 r/min?
The lower figure, 5,700 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-2580/2523 at 7,600 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.