72188C-72487 bearing: complete specifications & equivalents
The 72188C-72487 is a ANSI ABMA 19.2 radial bearing sized 47.625 x 123.825 x 36.512 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 47.625 mm |
| Outer diameter D | 123.825 mm |
| Width B | 36.512 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 171 kN |
| Basic static load rating C0 | 188 kN |
| Limiting speed (mechanical) | 2900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2160 g |
| Manufacturer designation | NTN 4T-72188C/72487 |
| 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 | 1.875 in |
|---|---|
| Outer diameter D | 4.875 in |
| Width B | 1.437 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 38.1 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) | 59 of 148 |
| Bore above smallest 4t-inch-series size | 34.925 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 72188C | 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 72188C-72487 model number is decoded
4T-72188C/72487 belongs to the NTN inch 4T tapered roller range (pure-numeric inch family); cone and cup are ordered by their own references and are individually interchangeable with like-numbered parts. Cone and cup of 4T-72188C/72487 are separately stocked parts: a worn 72487 cup can be replaced against the existing 72188C cone, provided the new cup carries the identical reference — pairing across references changes the 36.512 mm assembled width and the rating. Selection: C 171 kN against C0 188 kN gives a C0/C ratio of 1.10 for the 47.625 mm bore; the pair is counted as one adjusted unit when checking L10 at the equivalent combined load. Cup-side note for 72487: within the pure-numeric inch family tables the 72188C cone is listed against several cup options, and it is the cup that fixes the 123.825 mm OD and the 36.512 mm assembled width — quote the full 72188C/72487 pair, never the cone alone. Minimum load matters at speed: an unloaded 4T-72188C/72487 run near 2,900 r/min lets the rollers skid; lightly spring-preload high-speed pair arrangements.
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 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
- Hub and pinion positions of this 47.625 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-72188C/72487.
- The pure-numeric inch family at 47.625 mm bore (123.825×36.512 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 72188C/72487 reference at purchase.
- Open 4T-72188C/72487 sets have no seals: a hub or gearbox needs external sealing or the 2,900 r/min grease figure is meaningless once water reaches the cone rib.
- ABMA makes the 47.625×123.825 mm envelope interchangeable, not the ratings: NTN prints 171/188 kN for this execution and another make of the same number can differ in roller complement.
- Shaft and housing fillets must clear the ring chamfers of 72188C and 72487; use undercut shoulders so the rings seat on the face, not on a radius.
- The 171/188 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-72188C/72487; 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-72188C/72487?
4T-72188C/72487 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 47.625 mm bore (1.875 in), 123.825 mm outside diameter and 36.512 mm assembled width T (4.875 × 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 171 kN, C0 188 kN, grease limiting speed 2,900 r/min, oil speed 3,900 r/min, mass about 2160 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-72188C/72487 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 72188C cone or the 72487 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 171/188 kN ratings change with the cup.
What is the difference between 4T-72188C/72487 and a metric ISO 355 tapered bearing?
4T-72188C/72487 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 47.625×123.825×36.512 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-72188C/72487 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 72188C/72487 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-72188C/72487 list two speeds, 2,900 and 3,900 r/min?
The lower figure, 2,900 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-72188C/72487 at 3,900 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.