861-854 bearing: complete specifications & equivalents
The 861-854 is a ANSI ABMA 19.2 radial bearing sized 101.6 x 190.5 x 57.15 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 101.6 mm |
| Outer diameter D | 190.5 mm |
| Width B | 57.15 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 420 kN |
| Basic static load rating C0 | 555 kN |
| Limiting speed (mechanical) | 2000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7000 g |
| Manufacturer designation | NTN 4T-861/854 |
| 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 in |
|---|---|
| Outer diameter D | 7.5 in |
| Width B | 2.25 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 44.5 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) | 119 of 148 |
| Bore above smallest 4t-inch-series size | 88.89999999999999 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 861 | 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 861-854 model number is decoded
For an inch shaft of 101.6 mm carrying combined radial and thrust load, NTN lists 4T-861/854, a single-row 4T tapered roller set of 420 kN C and 555 kN C0 inside the 190.5 mm OD cup. 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 — 861 sits in the pure-numeric inch family. The 44.5 mm radial section over the 101.6 mm bore positions the contact line of the pair; abutment shoulders and spacers are dimensioned from that geometry, not from the bore alone. Cup-side note for 854: within the pure-numeric inch family tables the 861 cone is listed against several cup options, and it is the cup that fixes the 190.5 mm OD and the 57.15 mm assembled width — quote the full 861/854 pair, never the cone alone. Minimum load matters at speed: an unloaded 4T-861/854 run near 2,000 r/min lets the rollers skid; lightly spring-preload high-speed pair arrangements.
Typical equipment & failure modes
Common applications
- paper-machine and calender roll supports
- off-highway and forestry machine axles
- marine winch and deck-machinery shafts
- crusher and screening-plant eccentric shafts
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- 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
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- Mount the 101.6 mm cone by induction heating (max 120 °C) and the 190.5 mm cup with a press sleeve; at 7000 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 101.6 mm bore (190.5×57.15 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 861/854 reference at purchase.
- Fit selection follows the rotating ring: a rotating cone on a 101.6 mm shaft takes a m6/n6 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Inch and metric bores collide on paper — 101.6 mm is 4 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- Grease packs must leave free volume inside the 57.15 mm-wide set; over-greasing a pair churning near the oil-band speed of 2,600 r/min raises temperature and destroys the setting.
- The 420/555 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-861/854; 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-861/854?
4T-861/854 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 101.6 mm bore (4 in), 190.5 mm outside diameter and 57.15 mm assembled width T (7.5 × 2.25 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 420 kN, C0 555 kN, grease limiting speed 2,000 r/min, oil speed 2,600 r/min, mass about 7000 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-861/854 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 861 cone or the 854 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 420/555 kN ratings change with the cup.
What is the difference between 4T-861/854 and a metric ISO 355 tapered bearing?
4T-861/854 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 101.6×190.5×57.15 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-861/854 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 861/854 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-861/854 list two speeds, 2,000 and 2,600 r/min?
The lower figure, 2,000 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-861/854 at 2,600 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.