3880-3820 bearing: complete specifications & equivalents
The 3880-3820 is a ANSI ABMA 19.2 radial bearing sized 41.275 x 85.725 x 30.162 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 41.275 mm |
| Outer diameter D | 85.725 mm |
| Width B | 30.162 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 116 kN |
| Basic static load rating C0 | 132 kN |
| Limiting speed (mechanical) | 4500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 814 g |
| Manufacturer designation | NTN 4T-3880/3820 |
| 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 | 1.625 in |
|---|---|
| Outer diameter D | 3.375 in |
| Width B | 1.187 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 22.2 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) | 47 of 148 |
| Bore above smallest 4t-inch-series size | 28.575 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 3880 | 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 3880-3820 model number is decoded
NTN supplies this 1.625 in (41.275 mm) shaft position as 4T-3880/3820: cone 3880, cup 3820, profiled rollers and a pressed-steel cage, rated 116 kN basic dynamic and 132 kN static. 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 — 3880 sits in the pure-numeric inch family. Grease relubrication at the 4,500 r/min limiting speed targets the cone-rib contact; sustaining 6,000 r/min needs an oil supply directed at the large roller ends. The printed 116/132 kN ratings belong to the assembled 3880+3820 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. A single-row tapered bearing reacts thrust in one direction only; 4T-3880/3820 is adjusted against a second bearing so the shaft is located in both directions.
Typical equipment & failure modes
Common applications
- industrial gearboxes built to inch shafting
- construction-equipment pivot and wheel positions
- mining and quarry conveyor drive pulleys
- machine-tool headstocks on inch spindles
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- 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
- indentation of the raceways by hard particles in an open, unsealed arrangement
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 41.275 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-3880/3820.
- The pure-numeric inch family at 41.275 mm bore (85.725×30.162 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 3880/3820 reference at purchase.
- Shaft and housing fillets must clear the ring chamfers of 3880 and 3820; use undercut shoulders so the rings seat on the face, not on a radius.
- ABMA makes the 41.275×85.725 mm envelope interchangeable, not the ratings: NTN prints 116/132 kN for this execution and another make of the same number can differ in roller complement.
- Do not confuse T (30.162 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- The 116/132 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-3880/3820; 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-3880/3820?
4T-3880/3820 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 41.275 mm bore (1.625 in), 85.725 mm outside diameter and 30.162 mm assembled width T (3.375 × 1.187 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 116 kN, C0 132 kN, grease limiting speed 4,500 r/min, oil speed 6,000 r/min, mass about 814 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-3880/3820 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 3880 cone or the 3820 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 116/132 kN ratings change with the cup.
What is the difference between 4T-3880/3820 and a metric ISO 355 tapered bearing?
4T-3880/3820 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 41.275×85.725×30.162 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-3880/3820 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 3880/3820 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-3880/3820 list two speeds, 4,500 and 6,000 r/min?
The lower figure, 4,500 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-3880/3820 at 6,000 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.