581-572 bearing: complete specifications & equivalents
The 581-572 is a ANSI ABMA 19.2 radial bearing sized 80.962 x 139.992 x 36.512 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 80.962 mm |
| Outer diameter D | 139.992 mm |
| Width B | 36.512 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 197 kN |
| Basic static load rating C0 | 265 kN |
| Limiting speed (mechanical) | 2600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2250 g |
| Manufacturer designation | NTN 4T-581/572 |
| 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 | 3.187 in |
|---|---|
| Outer diameter D | 5.511 in |
| Width B | 1.437 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 29.5 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) | 98 of 148 |
| Bore above smallest 4t-inch-series size | 68.262 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 581 | 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 581-572 model number is decoded
4T-581/572 is an NTN inch-series single-row tapered roller bearing: a separable cone-and-cup pair on the ABMA inch boundary plan, 80.962×139.992×36.512 mm (assembled width T), for a shaft of about 80.962 mm (3.187 in). 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 581/572 without it. Selection: C 197 kN against C0 265 kN gives a C0/C ratio of 1.35 for the 80.962 mm bore; the pair is counted as one adjusted unit when checking L10 at the equivalent combined load. The printed 197/265 kN ratings belong to the assembled 581+572 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. Running clearance of 4T-581/572 is set at mounting by axial displacement of cone or cup — the catalogue does not ship a preloaded set, so the drawing must state end play or preload.
Typical equipment & failure modes
Common applications
- marine winch and deck-machinery shafts
- crusher and screening-plant eccentric shafts
- heavy truck and bus drive-axle differentials
- plant gearboxes on inch-dimensioned shaft lines
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- 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
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- Mount the 80.962 mm cone by induction heating (max 120 °C) and the 139.992 mm cup with a press sleeve; at 2250 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 80.962 mm bore (139.992×36.512 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 581/572 reference at purchase.
- Open 4T-581/572 sets have no seals: a hub or gearbox needs external sealing or the 2,600 r/min grease figure is meaningless once water reaches the cone rib.
- Shaft and housing fillets must clear the ring chamfers of 581 and 572; use undercut shoulders so the rings seat on the face, not on a radius.
- Inch and metric bores collide on paper — 80.962 mm is 3.187 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- The 197/265 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-581/572; 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-581/572?
4T-581/572 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 80.962 mm bore (3.187 in), 139.992 mm outside diameter and 36.512 mm assembled width T (5.511 × 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 197 kN, C0 265 kN, grease limiting speed 2,600 r/min, oil speed 3,400 r/min, mass about 2250 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-581/572 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 581 cone or the 572 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 197/265 kN ratings change with the cup.
What is the difference between 4T-581/572 and a metric ISO 355 tapered bearing?
4T-581/572 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 80.962×139.992×36.512 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-581/572 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 581/572 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-581/572 list two speeds, 2,600 and 3,400 r/min?
The lower figure, 2,600 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-581/572 at 3,400 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.