33890-33821 bearing: complete specifications & equivalents
The 33890-33821 is a ANSI ABMA 19.2 radial bearing sized 52.388 x 95.25 x 27.783 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 52.388 mm |
| Outer diameter D | 95.25 mm |
| Width B | 27.783 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 119 kN |
| Basic static load rating C0 | 139 kN |
| Limiting speed (mechanical) | 3900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 851 g |
| Manufacturer designation | NTN 4T-33890/33821 |
| 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 | 2.063 in |
|---|---|
| Outer diameter D | 3.75 in |
| Width B | 1.094 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 21.4 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) | 66 of 148 |
| Bore above smallest 4t-inch-series size | 39.688 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33890 | 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 33890-33821 model number is decoded
4T-33890/33821 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. The 4T prefix is NTN's tapered roller quality mark stamped on both parts; it is a brand mark, not a size code, so cross-references quote 33890/33821 without it. The 21.4 mm radial section over the 52.388 mm bore positions the contact line of the pair; abutment shoulders and spacers are dimensioned from that geometry, not from the bore alone. Housing fitment sequence for 4T-33890/33821: press the 33821 cup square into the 95.25 mm seat first, then bring the 33890 cone (on its 52.388 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. The rollers run with their large ends against the cone's guide rib; lubricant must reach that rib face of 4T-33890/33821, not only the raceway, or the pair smears on the first overloaded start.
Typical equipment & failure modes
Common applications
- mining and quarry conveyor drive pulleys
- machine-tool headstocks on inch spindles
- pump and blower drive shafts with combined load
- truck and trailer axle hubs on inch-dimensioned axles
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- 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
- edge loading when shaft deflection exceeds the few arc-minutes an adjusted pair tolerates
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 52.388 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-33890/33821.
- The pure-numeric inch family at 52.388 mm bore (95.25×27.783 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 33890/33821 reference at purchase.
- Do not confuse T (27.783 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- Never drive the 95.25 mm cup home through the rollers: fitting force goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Inch and metric bores collide on paper — 52.388 mm is 2.063 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- The 119/139 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-33890/33821; 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-33890/33821?
4T-33890/33821 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 52.388 mm bore (2.063 in), 95.25 mm outside diameter and 27.783 mm assembled width T (3.75 × 1.094 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 119 kN, C0 139 kN, grease limiting speed 3,900 r/min, oil speed 5,200 r/min, mass about 851 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-33890/33821 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 33890 cone or the 33821 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 119/139 kN ratings change with the cup.
What is the difference between 4T-33890/33821 and a metric ISO 355 tapered bearing?
4T-33890/33821 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 52.388×95.25×27.783 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-33890/33821 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 33890/33821 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-33890/33821 list two speeds, 3,900 and 5,200 r/min?
The lower figure, 3,900 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-33890/33821 at 5,200 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.