2796-2729 bearing: complete specifications & equivalents
The 2796-2729 is a ANSI ABMA 19.2 radial bearing sized 34.925 x 76.2 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 | 34.925 mm |
| Outer diameter D | 76.2 mm |
| Width B | 23.812 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 81 kN |
| Basic static load rating C0 | 90.5 kN |
| Limiting speed (mechanical) | 5100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 536 g |
| Manufacturer designation | NTN 4T-2796/2729 |
| 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 | 1.375 in |
|---|---|
| Outer diameter D | 3 in |
| Width B | 0.937 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20.6 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) | 34 of 148 |
| Bore above smallest 4t-inch-series size | 22.224999999999998 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 2796 | 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 2796-2729 model number is decoded
NTN supplies this 1.375 in (34.925 mm) shaft position as 4T-2796/2729: cone 2796, cup 2729, profiled rollers and a pressed-steel cage, rated 81 kN basic dynamic and 90.5 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 2796/2729 without it. Contact-angle geometry of the pure-numeric inch family gives 4T-2796/2729 its radial/axial load split — at 81/90.5 kN the static rating is about 1.12× C, typical of inch tapered sets proportioned for combined duty. The printed 81/90.5 kN ratings belong to the assembled 2796+2729 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. Mount the 34.925 mm cone with an induction heater (max 120 °C) and press the 76.2 mm cup with a sleeve; driving either ring through the rollers brinells the raceways.
Typical equipment & failure modes
Common applications
- pump and blower drive shafts with combined load
- truck and trailer axle hubs on inch-dimensioned axles
- agricultural tractor transmission and PTO shafts
- industrial gearboxes built to inch shafting
Known failure patterns
- cone-rib and roller large-end smearing when the adjusted pair runs with preload but starved lubricant film
- preload loss and noise after one bearing of the adjusted pair is replaced without resetting end play
- false brinelling on a stationary pair exposed to vibration during transport or standby
- cage damage from a mounting blow transmitted through the roller complement
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 34.925 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-2796/2729.
- The pure-numeric inch family at 34.925 mm bore (76.2×23.812 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 2796/2729 reference at purchase.
- Fit selection follows the rotating ring: a rotating cone on a 34.925 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Quote the full 2796/2729 pair at ordering: the 2796 cone also ships against sibling cups, and a cup from another reference changes the 23.812 mm assembled width and the rating.
- Grease packs must leave free volume inside the 23.812 mm-wide set; over-greasing a pair churning near the oil-band speed of 6,800 r/min raises temperature and destroys the setting.
- The 81/90.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-2796/2729; 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-2796/2729?
4T-2796/2729 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 34.925 mm bore (1.375 in), 76.2 mm outside diameter and 23.812 mm assembled width T (3 × 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 81 kN, C0 90.5 kN, grease limiting speed 5,100 r/min, oil speed 6,800 r/min, mass about 536 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-2796/2729 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 2796 cone or the 2729 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 81/90.5 kN ratings change with the cup.
What is the difference between 4T-2796/2729 and a metric ISO 355 tapered bearing?
4T-2796/2729 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 34.925×76.2×23.812 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-2796/2729 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 2796/2729 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-2796/2729 list two speeds, 5,100 and 6,800 r/min?
The lower figure, 5,100 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-2796/2729 at 6,800 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.