29585-29521 bearing: complete specifications & equivalents
The 29585-29521 is a ANSI ABMA 19.2 radial bearing sized 63.5 x 110 x 25.4 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 63.5 mm |
| Outer diameter D | 110 mm |
| Width B | 25.4 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 101 kN |
| Basic static load rating C0 | 140 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 982 g |
| Manufacturer designation | NTN 4T-29585/29521 |
| 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 | 2.5 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 1 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 23.3 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) | 81 of 148 |
| Bore above smallest 4t-inch-series size | 50.8 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29585-29520 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN cone 4T-29585 paired with a different cup (29520): 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 29585-29521 model number is decoded
4T-29585/29521 is an NTN inch-series single-row tapered roller bearing: a separable cone-and-cup pair on the ABMA inch boundary plan, 63.5×110×25.4 mm (assembled width T), for a shaft of about 63.5 mm (2.5 in). Letter prefixes inherited from the inch convention mark the load family: LM reads as light-medium, HM as heavy-medium, LL as extra-light, J-prefixed codes as metric-envelope families — 29585 sits in the pure-numeric inch family. Contact-angle geometry of the pure-numeric inch family gives 4T-29585/29521 its radial/axial load split — at 101/140 kN the static rating is about 1.39× C, typical of inch tapered sets proportioned for combined duty. Cup-side note for 29521: within the pure-numeric inch family tables the 29585 cone is listed against several cup options, and it is the cup that fixes the 110 mm OD and the 25.4 mm assembled width — quote the full 29585/29521 pair, never the cone alone. Fillet radii must clear the chamfers of the 29585 cone and 29521 cup; undercut shoulders seat the rings fully instead of bridging on a radius.
Typical equipment & failure modes
Common applications
- off-highway and forestry machine axles
- marine winch and deck-machinery shafts
- crusher and screening-plant eccentric shafts
- heavy truck and bus drive-axle differentials
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
- cage fatigue when the pair runs continuously near the grease limiting speed without oil cooling
- rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- Mount the 63.5 mm cone by induction heating (max 120 °C) and the 110 mm cup with a press sleeve; at 982 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 63.5 mm bore (110×25.4 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 29585/29521 reference at purchase.
- Open 4T-29585/29521 sets have no seals: a hub or gearbox needs external sealing or the 3,200 r/min grease figure is meaningless once water reaches the cone rib.
- An unloaded 4T-29585/29521 near 3,200 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- Grease packs must leave free volume inside the 25.4 mm-wide set; over-greasing a pair churning near the oil-band speed of 4,300 r/min raises temperature and destroys the setting.
- The 101/140 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-29585/29521; 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-29585/29521?
4T-29585/29521 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 63.5 mm bore (2.5 in), 110 mm outside diameter and 25.4 mm assembled width T (4.331 × 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 101 kN, C0 140 kN, grease limiting speed 3,200 r/min, oil speed 4,300 r/min, mass about 982 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-29585/29521 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 29585 cone or the 29521 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 101/140 kN ratings change with the cup.
What is the difference between 4T-29585/29521 and a metric ISO 355 tapered bearing?
4T-29585/29521 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 63.5×110×25.4 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-29585/29521 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 29585/29521 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-29585/29521 list two speeds, 3,200 and 4,300 r/min?
The lower figure, 3,200 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-29585/29521 at 4,300 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.