47487-47420-NTN bearing: complete specifications & equivalents
The 47487-47420-NTN is a ANSI ABMA 19.2 radial bearing sized 69.85 x 120 x 32.545 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 mm |
| Width B | 32.545 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 163 kN |
| Basic static load rating C0 | 214 kN |
| Limiting speed (mechanical) | 3000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1630 g |
| Manufacturer designation | NTN 4T-47487/47420 |
| 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 | 4.724 in |
| Width B | 1.281 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25.1 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 |
|---|---|---|---|
| 47487-47420 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 69.85×120×32.545 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 47487-47420A | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 69.85×120×32.545 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application 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 47487-47420-NTN model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-47487/47420 denotes the pure-numeric inch family of NTN inch tapered roller bearings — cone 47487 and cup 47420 delivered as a matched, separable pair of 69.85 mm bore and 120 mm outside diameter. 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 — 47487 sits in the pure-numeric inch family. Catalogue mass of the 4T-47487/47420 cone-plus-cup set is 1630 g; shaft and housing shoulders must carry that mass square to the axis during fitting. The printed 163/214 kN ratings belong to the assembled 47487+47420 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. Minimum load matters at speed: an unloaded 4T-47487/47420 run near 3,000 r/min lets the rollers skid; lightly spring-preload high-speed pair arrangements.
Typical equipment & failure modes
Common applications
- large conveyor head pulleys in bulk-handling plant
- paper-machine and calender roll supports
- off-highway and forestry machine axles
- marine winch and deck-machinery shafts
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
- 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 69.85 mm cone by induction heating (max 120 °C) and the 120 mm cup with a press sleeve; at 1630 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 69.85 mm bore (120×32.545 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 47487/47420 reference at purchase.
- Quote the full 47487/47420 pair at ordering: the 47487 cone also ships against sibling cups, and a cup from another reference changes the 32.545 mm assembled width and the rating.
- An unloaded 4T-47487/47420 near 3,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- Do not confuse T (32.545 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- The 163/214 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-47487/47420; 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-47487/47420?
4T-47487/47420 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 69.85 mm bore (2.75 in), 120 mm outside diameter and 32.545 mm assembled width T (4.724 × 1.281 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 163 kN, C0 214 kN, grease limiting speed 3,000 r/min, oil speed 4,000 r/min, mass about 1630 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-47487/47420 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 47487 cone or the 47420 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 163/214 kN ratings change with the cup.
What is the difference between 4T-47487/47420 and a metric ISO 355 tapered bearing?
4T-47487/47420 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 69.85×120×32.545 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-47487/47420 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 47487/47420 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-47487/47420 list two speeds, 3,000 and 4,000 r/min?
The lower figure, 3,000 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-47487/47420 at 4,000 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.