A6075-A6157 bearing: complete specifications & equivalents
The A6075-A6157 is a ANSI ABMA 19.2 radial bearing sized 19.05 x 39.992 x 12.014 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 19.05 mm |
| Outer diameter D | 39.992 mm |
| Width B | 12.014 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 14.2 kN |
| Basic static load rating C0 | 12.8 kN |
| Limiting speed (mechanical) | 10000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 65 g |
| Manufacturer designation | NTN 4T-A6075/A6157 |
| 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 | 0.75 in |
|---|---|
| Outer diameter D | 1.574 in |
| Width B | 0.473 in |
| ISO bore code | 75 |
| Radial section height (D−d)/2 | 10.5 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) | 6 of 148 |
| Bore above smallest 4t-inch-series size | 6.350000000000001 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| A6075 | 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 A6075-A6157 model number is decoded
4T-A6075/A6157 is the NTN 4T catalogue entry for a 19.05×39.992×12.014 mm inch tapered roller bearing — an ABMA-dimensioned cone/cup set, not an ISO 355 metric bearing, even though the table quotes metric equivalents. 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 — A6075 sits in the A small-size family. Imperial cross-check for the drawing: 19.05×39.992×12.014 mm converts to 0.75 × 1.574 × 0.473 in; the ABMA envelope swaps with like-numbered inch parts but the 14.2/12.8 kN ratings are NTN-specific. The printed 14.2/12.8 kN ratings belong to the assembled A6075+A6157 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. With a rotating shaft a k5/m5 cone seat and an easy-push cup seat are typical practice for 4T-A6075/A6157; reverse the fit logic when the cup rotates.
Typical equipment & failure modes
Common applications
- lawn, garden and powersport axle positions
- small inch-shaft gearbox and reducer shafts
- conveyor roller and pulley shafts in inch-frame machinery
- utility-vehicle differential and pinion supports
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 damage from a mounting blow transmitted through the roller complement
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- At 19.05 mm (0.75 in) bore the thin cone and cup distort under an over-tight shaft nut; set the 4T-A6075/A6157 pair with a dial indicator on end play rather than by locknut feel.
- The A small-size family at 19.05 mm bore (39.992×12.014 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full A6075/A6157 reference at purchase.
- An unloaded 4T-A6075/A6157 near 10,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- Open 4T-A6075/A6157 sets have no seals: a hub or gearbox needs external sealing or the 10,000 r/min grease figure is meaningless once water reaches the cone rib.
- Quote the full A6075/A6157 pair at ordering: the A6075 cone also ships against sibling cups, and a cup from another reference changes the 12.014 mm assembled width and the rating.
- The 14.2/12.8 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-A6075/A6157; 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-A6075/A6157?
4T-A6075/A6157 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 19.05 mm bore (0.75 in), 39.992 mm outside diameter and 12.014 mm assembled width T (1.574 × 0.473 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14.2 kN, C0 12.8 kN, grease limiting speed 10,000 r/min, oil speed 13,000 r/min, mass about 65 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-A6075/A6157 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the A6075 cone or the A6157 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 14.2/12.8 kN ratings change with the cup.
What is the difference between 4T-A6075/A6157 and a metric ISO 355 tapered bearing?
4T-A6075/A6157 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 19.05×39.992×12.014 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-A6075/A6157 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 A6075/A6157 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-A6075/A6157 list two speeds, 10,000 and 13,000 r/min?
The lower figure, 10,000 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-A6075/A6157 at 13,000 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.