44150-44348 bearing: complete specifications & equivalents
The 44150-44348 is a ANSI ABMA 19.2 radial bearing sized 38.1 x 88.5 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 | 38.1 mm |
| Outer diameter D | 88.5 mm |
| Width B | 25.4 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 78.5 kN |
| Basic static load rating C0 | 78 kN |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 714 g |
| Manufacturer designation | NTN 4T-44150/44348 |
| 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 | 1.5 in |
|---|---|
| Outer diameter D | 3.484 in |
| Width B | 1 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25.2 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) | 42 of 148 |
| Bore above smallest 4t-inch-series size | 25.400000000000002 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 44150 | 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 44150-44348 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-44150/44348 denotes the pure-numeric inch family of NTN inch tapered roller bearings — cone 44150 and cup 44348 delivered as a matched, separable pair of 38.1 mm bore and 88.5 mm outside diameter. Unlike ISO 355 metric numbers, this ABMA code does not encode the bore arithmetically: 44150 identifies the cone of 38.1 mm (1.5 in) bore by catalogue lookup, and 44348 fixes the 88.5 mm OD. Contact-angle geometry of the pure-numeric inch family gives 4T-44150/44348 its radial/axial load split — at 78.5/78 kN the static rating is about 0.99× C, typical of inch tapered sets proportioned for combined duty. Cup-side note for 44348: within the pure-numeric inch family tables the 44150 cone is listed against several cup options, and it is the cup that fixes the 88.5 mm OD and the 25.4 mm assembled width — quote the full 44150/44348 pair, never the cone alone. A single-row tapered bearing reacts thrust in one direction only; 4T-44150/44348 is adjusted against a second bearing so the shaft is located in both directions.
Typical equipment & failure modes
Common applications
- machine-tool headstocks on inch spindles
- pump and blower drive shafts with combined load
- truck and trailer axle hubs on inch-dimensioned axles
- agricultural tractor transmission and PTO shafts
Known failure patterns
- cone-rib and roller large-end smearing when the adjusted pair runs with preload but starved lubricant film
- flaking on one cone only when a bent shaft loads the O/X pair unevenly
- cup creep and housing fretting when the cup seat is cut too loose for the rotating load
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- brinell marks on cone and cup raceways from impact during handling or hammer fitting
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 38.1 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-44150/44348.
- The pure-numeric inch family at 38.1 mm bore (88.5×25.4 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 44150/44348 reference at purchase.
- Fit selection follows the rotating ring: a rotating cone on a 38.1 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Open 4T-44150/44348 sets have no seals: a hub or gearbox needs external sealing or the 4,000 r/min grease figure is meaningless once water reaches the cone rib.
- Shaft and housing fillets must clear the ring chamfers of 44150 and 44348; use undercut shoulders so the rings seat on the face, not on a radius.
- The 78.5/78 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-44150/44348; 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-44150/44348?
4T-44150/44348 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 38.1 mm bore (1.5 in), 88.5 mm outside diameter and 25.4 mm assembled width T (3.484 × 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 78.5 kN, C0 78 kN, grease limiting speed 4,000 r/min, oil speed 5,300 r/min, mass about 714 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-44150/44348 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 44150 cone or the 44348 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 78.5/78 kN ratings change with the cup.
What is the difference between 4T-44150/44348 and a metric ISO 355 tapered bearing?
4T-44150/44348 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 38.1×88.5×25.4 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-44150/44348 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 44150/44348 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-44150/44348 list two speeds, 4,000 and 5,300 r/min?
The lower figure, 4,000 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-44150/44348 at 5,300 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.