397-394A bearing: complete specifications & equivalents
The 397-394A is a ANSI ABMA 19.2 radial bearing sized 60 x 110 x 22 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 60 mm |
| Outer diameter D | 110 mm |
| Width B | 22 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 99.5 kN |
| Basic static load rating C0 | 120 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 918 g |
| Manufacturer designation | NTN 4T-397/394A |
| 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 | 2.362 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 0.866 in |
| ISO bore code | 97 |
| Radial section height (D−d)/2 | 25 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) | 76 of 148 |
| Bore above smallest 4t-inch-series size | 47.3 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 397 | 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 397-394A model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-397/394A denotes the pure-numeric inch family of NTN inch tapered roller bearings — cone 397 and cup 394A delivered as a matched, separable pair of 60 mm bore and 110 mm outside diameter. 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 — 397 sits in the pure-numeric inch family. Speed planning uses both catalogue columns: grease 3,200 r/min is the mechanical ceiling for 4T-397/394A, oil 4,300 r/min with circulating oil — a 1,100 r/min margin at this size. Cup-side note for 394A: within the pure-numeric inch family tables the 397 cone is listed against several cup options, and it is the cup that fixes the 110 mm OD and the 22 mm assembled width — quote the full 397/394A pair, never the cone alone. Minimum load matters at speed: an unloaded 4T-397/394A run near 3,200 r/min lets the rollers skid; lightly spring-preload high-speed pair arrangements.
Typical equipment & failure modes
Common applications
- plant gearboxes on inch-dimensioned shaft lines
- large conveyor head pulleys in bulk-handling plant
- paper-machine and calender roll supports
- off-highway and forestry machine 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
- rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- Mount the 60 mm cone by induction heating (max 120 °C) and the 110 mm cup with a press sleeve; at 918 g a cocked ring brinells the raceway directly.
- The pure-numeric inch family at 60 mm bore (110×22 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 397/394A reference at purchase.
- Shaft and housing fillets must clear the ring chamfers of 397 and 394A; use undercut shoulders so the rings seat on the face, not on a radius.
- Fit selection follows the rotating ring: a rotating cone on a 60 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Never drive the 110 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.
- The 99.5/120 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-397/394A; 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-397/394A?
4T-397/394A is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 60 mm bore (2.362 in), 110 mm outside diameter and 22 mm assembled width T (4.331 × 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 99.5 kN, C0 120 kN, grease limiting speed 3,200 r/min, oil speed 4,300 r/min, mass about 918 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-397/394A interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 397 cone or the 394A 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 99.5/120 kN ratings change with the cup.
What is the difference between 4T-397/394A and a metric ISO 355 tapered bearing?
4T-397/394A 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 60×110×22 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-397/394A 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 397/394A references; the 4T spelling is retained among this page's search aliases.
Why does 4T-397/394A list two speeds, 3,200 and 4,300 r/min?
The lower figure, 3,200 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-397/394A at 4,300 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.