358-354A bearing: complete specifications & equivalents
The 358-354A is a ANSI ABMA 19.2 radial bearing sized 44.983 x 85 x 20.638 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 44.983 mm |
| Outer diameter D | 85 mm |
| Width B | 20.638 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 77.5 kN |
| Basic static load rating C0 | 79.5 kN |
| Limiting speed (mechanical) | 4400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 505 g |
| Manufacturer designation | NTN 4T-358/354A |
| 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 | 1.771 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 0.813 in |
| ISO bore code | 58 |
| Radial section height (D−d)/2 | 20 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) | 52 of 148 |
| Bore above smallest 4t-inch-series size | 32.283 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 358 | 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 358-354A model number is decoded
For an inch shaft of 44.983 mm carrying combined radial and thrust load, NTN lists 4T-358/354A, a single-row 4T tapered roller set of 77.5 kN C and 79.5 kN C0 inside the 85 mm OD cup. Reading the designation: 4T-358/354A follows the ABMA inch convention — the number before the slash is the cone (inner ring with roller set and cage), the number after the slash is the cup (outer ring), and the pure-numeric inch family lettering ties the pair to its boundary plan. Two single-row inch sets are normally mounted as an adjusted O or X pair; the 20.638 mm T of each 4T-358/354A enters the spacer calculation, so the tolerance on assembled width matters as much as the bore fit. The printed 77.5/79.5 kN ratings belong to the assembled 358+354A 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. Fillet radii must clear the chamfers of the 358 cone and 354A cup; undercut shoulders seat the rings fully instead of bridging on a radius.
Typical equipment & failure modes
Common applications
- machine-tool headstocks on inch spindles
- pump and blower drive shafts with combined load
- truck and trailer axle hubs on inch-dimensioned axles
- agricultural tractor transmission and PTO shafts
Known failure patterns
- cone-rib and roller large-end smearing when the adjusted pair runs with preload but starved lubricant film
- cup creep and housing fretting when the cup seat is cut too loose for the rotating load
- flaking on one cone only when a bent shaft loads the O/X pair unevenly
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 44.983 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-358/354A.
- The pure-numeric inch family at 44.983 mm bore (85×20.638 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 358/354A reference at purchase.
- Replacing one half of an adjusted pair without resetting end play negates the 20.638 mm T logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Open 4T-358/354A sets have no seals: a hub or gearbox needs external sealing or the 4,400 r/min grease figure is meaningless once water reaches the cone rib.
- An unloaded 4T-358/354A near 4,400 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- The 77.5/79.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-358/354A; 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-358/354A?
4T-358/354A is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 44.983 mm bore (1.771 in), 85 mm outside diameter and 20.638 mm assembled width T (3.346 × 0.813 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 77.5 kN, C0 79.5 kN, grease limiting speed 4,400 r/min, oil speed 5,800 r/min, mass about 505 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-358/354A interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 358 cone or the 354A 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 77.5/79.5 kN ratings change with the cup.
What is the difference between 4T-358/354A and a metric ISO 355 tapered bearing?
4T-358/354A 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 44.983×85×20.638 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-358/354A 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 358/354A references; the 4T spelling is retained among this page's search aliases.
Why does 4T-358/354A list two speeds, 4,400 and 5,800 r/min?
The lower figure, 4,400 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-358/354A at 5,800 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.