29675-29630 bearing: complete specifications & equivalents
The 29675-29630 is a ANSI ABMA 19.2 radial bearing sized 69.85 x 120.65 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 | 69.85 mm |
| Outer diameter D | 120.65 mm |
| Width B | 25.4 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 106 kN |
| Basic static load rating C0 | 151 kN |
| Limiting speed (mechanical) | 3100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1170 g |
| Manufacturer designation | NTN 4T-29675/29630 |
| 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 | 2.75 in |
|---|---|
| Outer diameter D | 4.75 in |
| Width B | 1 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25.4 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) | 86 of 148 |
| Bore above smallest 4t-inch-series size | 57.14999999999999 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29675-29620-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN cone 4T-29675 paired with a different cup (29620): cone interchangeable, cup differs — OD, assembled width T and ratings follow the cup. Verify the full cone/cup reference before substituting. |
| 29675-29620 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
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 29675-29630 model number is decoded
The NTN 2203E inch table prints 4T-29675/29630 at 69.85 mm bore (2.75 in), 120.65 mm cup OD and 25.4 mm assembled T, with a grease limiting speed of 3,100 r/min and an oil ceiling of 4,100 r/min. Unlike ISO 355 metric numbers, this ABMA code does not encode the bore arithmetically: 29675 identifies the cone of 69.85 mm (2.75 in) bore by catalogue lookup, and 29630 fixes the 120.65 mm OD. The 1.5 kN of dynamic capacity per millimetre of bore summarises the 106 kN rating over the 69.85 mm bore — sanity-check any interchange candidate against this ratio and the 25.4 mm T. The printed 106/151 kN ratings belong to the assembled 29675+29630 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. The rollers run with their large ends against the cone's guide rib; lubricant must reach that rib face of 4T-29675/29630, not only the raceway, or the pair smears on the first overloaded start.
Typical equipment & failure modes
Common applications
- crusher and screening-plant eccentric shafts
- heavy truck and bus drive-axle differentials
- plant gearboxes on inch-dimensioned shaft lines
- large conveyor head pulleys in bulk-handling plant
Known failure patterns
- cone-rib and roller large-end smearing when the adjusted pair runs with preload but starved lubricant film
- false brinelling on a stationary pair exposed to vibration during transport or standby
- preload loss and noise after one bearing of the adjusted pair is replaced without resetting end play
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- indentation of the raceways by hard particles in an open, unsealed arrangement
Selection pitfalls — read before you substitute
- Mount the 69.85 mm cone by induction heating (max 120 °C) and the 120.65 mm cup with a press sleeve; at 1170 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 69.85 mm bore (120.65×25.4 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 29675/29630 reference at purchase.
- Inch and metric bores collide on paper — 69.85 mm is 2.75 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- Grease packs must leave free volume inside the 25.4 mm-wide set; over-greasing a pair churning near the oil-band speed of 4,100 r/min raises temperature and destroys the setting.
- Grease packs must leave free volume inside the 25.4 mm-wide set; over-greasing a pair churning near the oil-band speed of 4,100 r/min raises temperature and destroys the setting.
- The 106/151 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-29675/29630; 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-29675/29630?
4T-29675/29630 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 69.85 mm bore (2.75 in), 120.65 mm outside diameter and 25.4 mm assembled width T (4.75 × 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 106 kN, C0 151 kN, grease limiting speed 3,100 r/min, oil speed 4,100 r/min, mass about 1170 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-29675/29630 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 29675 cone or the 29630 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 106/151 kN ratings change with the cup.
What is the difference between 4T-29675/29630 and a metric ISO 355 tapered bearing?
4T-29675/29630 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 69.85×120.65×25.4 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-29675/29630 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 29675/29630 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-29675/29630 list two speeds, 3,100 and 4,100 r/min?
The lower figure, 3,100 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-29675/29630 at 4,100 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.