05066-05185 bearing: complete specifications & equivalents
The 05066-05185 is a ANSI ABMA 19.2 radial bearing sized 16.993 x 47 x 14.381 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 16.993 mm |
| Outer diameter D | 47 mm |
| Width B | 14.381 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 26.6 kN |
| Basic static load rating C0 | 24.2 kN |
| Limiting speed (mechanical) | 8600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 130 g |
| Manufacturer designation | NTN 4T-05066/05185 |
| 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.566 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 15 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) | 4 of 148 |
| Bore above smallest 4t-inch-series size | 4.292999999999999 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 05066 | 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 05066-05185 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-05066/05185 denotes the pure-numeric inch family of NTN inch tapered roller bearings — cone 05066 and cup 05185 delivered as a matched, separable pair of 16.993 mm bore and 47 mm outside diameter. Cone and cup of 4T-05066/05185 are separately stocked parts: a worn 05185 cup can be replaced against the existing 05066 cone, provided the new cup carries the identical reference — pairing across references changes the 14.381 mm assembled width and the rating. Selection: C 26.6 kN against C0 24.2 kN gives a C0/C ratio of 0.91 for the 16.993 mm bore; the pair is counted as one adjusted unit when checking L10 at the equivalent combined load. The printed 26.6/24.2 kN ratings belong to the assembled 05066+05185 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. Running clearance of 4T-05066/05185 is set at mounting by axial displacement of cone or cup — the catalogue does not ship a preloaded set, so the drawing must state end play or preload.
Typical equipment & failure modes
Common applications
- small inch-shaft gearbox and reducer shafts
- conveyor roller and pulley shafts in inch-frame machinery
- utility-vehicle differential and pinion supports
- small machine-tool feed and spindle counter-supports
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
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- At 16.993 mm (0.669 in) bore the thin cone and cup distort under an over-tight shaft nut; set the 4T-05066/05185 pair with a dial indicator on end play rather than by locknut feel.
- The pure-numeric inch family at 16.993 mm bore (47×14.381 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 05066/05185 reference at purchase.
- Inch and metric bores collide on paper — 16.993 mm is 0.669 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- Fit selection follows the rotating ring: a rotating cone on a 16.993 mm shaft takes a j5/k5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Do not confuse T (14.381 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- The 26.6/24.2 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-05066/05185; 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-05066/05185?
4T-05066/05185 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 16.993 mm bore (0.669 in), 47 mm outside diameter and 14.381 mm assembled width T (1.85 × 0.566 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 26.6 kN, C0 24.2 kN, grease limiting speed 8,600 r/min, oil speed 11,000 r/min, mass about 130 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-05066/05185 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 05066 cone or the 05185 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 26.6/24.2 kN ratings change with the cup.
What is the difference between 4T-05066/05185 and a metric ISO 355 tapered bearing?
4T-05066/05185 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 16.993×47×14.381 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-05066/05185 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 05066/05185 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-05066/05185 list two speeds, 8,600 and 11,000 r/min?
The lower figure, 8,600 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-05066/05185 at 11,000 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.