47686-47620 bearing: complete specifications & equivalents
The 47686-47620 is a ANSI ABMA 19.2 radial bearing sized 82.55 x 133.35 x 33.338 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 82.55 mm |
| Outer diameter D | 133.35 mm |
| Width B | 33.338 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 170 kN |
| Basic static load rating C0 | 235 kN |
| Limiting speed (mechanical) | 2600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1720 g |
| Manufacturer designation | NTN 4T-47686/47620 |
| 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 | 3.25 in |
|---|---|
| Outer diameter D | 5.25 in |
| Width B | 1.313 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) | 99 of 148 |
| Bore above smallest 4t-inch-series size | 69.85 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 47686 | 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 47686-47620 model number is decoded
For an inch shaft of 82.55 mm carrying combined radial and thrust load, NTN lists 4T-47686/47620, a single-row 4T tapered roller set of 170 kN C and 235 kN C0 inside the 133.35 mm OD cup. 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 — 47686 sits in the pure-numeric inch family. Two single-row inch sets are normally mounted as an adjusted O or X pair; the 33.338 mm T of each 4T-47686/47620 enters the spacer calculation, so the tolerance on assembled width matters as much as the bore fit. Housing fitment sequence for 4T-47686/47620: press the 47620 cup square into the 133.35 mm seat first, then bring the 47686 cone (on its 82.55 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. Running clearance of 4T-47686/47620 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
- 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 fatigue when the pair runs continuously near the grease limiting speed without oil cooling
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- Mount the 82.55 mm cone by induction heating (max 120 °C) and the 133.35 mm cup with a press sleeve; at 1720 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 82.55 mm bore (133.35×33.338 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 47686/47620 reference at purchase.
- Shaft and housing fillets must clear the ring chamfers of 47686 and 47620; use undercut shoulders so the rings seat on the face, not on a radius.
- Fit selection follows the rotating ring: a rotating cone on a 82.55 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Do not confuse T (33.338 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- The 170/235 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-47686/47620; 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-47686/47620?
4T-47686/47620 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 82.55 mm bore (3.25 in), 133.35 mm outside diameter and 33.338 mm assembled width T (5.25 × 1.313 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 170 kN, C0 235 kN, grease limiting speed 2,600 r/min, oil speed 3,500 r/min, mass about 1720 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-47686/47620 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 47686 cone or the 47620 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 170/235 kN ratings change with the cup.
What is the difference between 4T-47686/47620 and a metric ISO 355 tapered bearing?
4T-47686/47620 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 82.55×133.35×33.338 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-47686/47620 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 47686/47620 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-47686/47620 list two speeds, 2,600 and 3,500 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-47686/47620 at 3,500 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.