37431-37625 bearing: complete specifications & equivalents
The 37431-37625 is a ANSI ABMA 19.2 radial bearing sized 109.538 x 158.75 x 23.02 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 109.538 mm |
| Outer diameter D | 158.75 mm |
| Width B | 23.02 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 114 kN |
| Basic static load rating C0 | 166 kN |
| Limiting speed (mechanical) | 2100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1320 g |
| Manufacturer designation | NTN 4T-37431/37625 |
| 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 | 4.313 in |
|---|---|
| Outer diameter D | 6.25 in |
| Width B | 0.906 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 24.6 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) | 122 of 148 |
| Bore above smallest 4t-inch-series size | 96.838 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 37431 | 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 37431-37625 model number is decoded
4T-37431/37625 is the NTN 4T catalogue entry for a 109.538×158.75×23.02 mm inch tapered roller bearing — an ABMA-dimensioned cone/cup set, not an ISO 355 metric bearing, even though the table quotes metric equivalents. Reading the designation: 4T-37431/37625 follows the ABMA inch convention — the number before the slash is the cone (inner ring with roller set and cage), the number after the slash is the cup (outer ring), and the pure-numeric inch family lettering ties the pair to its boundary plan. Grease relubrication at the 2,100 r/min limiting speed targets the cone-rib contact; sustaining 2,800 r/min needs an oil supply directed at the large roller ends. The printed 114/166 kN ratings belong to the assembled 37431+37625 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-37431/37625 run near 2,100 r/min lets the rollers skid; lightly spring-preload high-speed pair arrangements.
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
- 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 damage from a mounting blow transmitted through the roller complement
- indentation of the raceways by hard particles in an open, unsealed arrangement
Selection pitfalls — read before you substitute
- Mount the 109.538 mm cone by induction heating (max 120 °C) and the 158.75 mm cup with a press sleeve; at 1320 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 109.538 mm bore (158.75×23.02 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 37431/37625 reference at purchase.
- Quote the full 37431/37625 pair at ordering: the 37431 cone also ships against sibling cups, and a cup from another reference changes the 23.02 mm assembled width and the rating.
- Grease packs must leave free volume inside the 23.02 mm-wide set; over-greasing a pair churning near the oil-band speed of 2,800 r/min raises temperature and destroys the setting.
- An unloaded 4T-37431/37625 near 2,100 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- The 114/166 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-37431/37625; 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-37431/37625?
4T-37431/37625 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 109.538 mm bore (4.313 in), 158.75 mm outside diameter and 23.02 mm assembled width T (6.25 × 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 114 kN, C0 166 kN, grease limiting speed 2,100 r/min, oil speed 2,800 r/min, mass about 1320 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-37431/37625 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 37431 cone or the 37625 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 114/166 kN ratings change with the cup.
What is the difference between 4T-37431/37625 and a metric ISO 355 tapered bearing?
4T-37431/37625 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 109.538×158.75×23.02 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-37431/37625 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 37431/37625 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-37431/37625 list two speeds, 2,100 and 2,800 r/min?
The lower figure, 2,100 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-37431/37625 at 2,800 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.