HM89446-HM89410 bearing: complete specifications & equivalents
The HM89446-HM89410 is a ANSI ABMA 19.2 radial bearing sized 34.925 x 76.2 x 29.37 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 34.925 mm |
| Outer diameter D | 76.2 mm |
| Width B | 29.37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 86.5 kN |
| Basic static load rating C0 | 105 kN |
| Limiting speed (mechanical) | 5100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 646 g |
| Manufacturer designation | NTN 4T-HM89446/HM89410 |
| 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 | 1.375 in |
|---|---|
| Outer diameter D | 3 in |
| Width B | 1.156 in |
| ISO bore code | 46 |
| Radial section height (D−d)/2 | 20.6 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) | 34 of 148 |
| Bore above smallest 4t-inch-series size | 22.224999999999998 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HM89446-410 | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
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 HM89446-HM89410 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-HM89446/HM89410 denotes the heavy-medium HM family of NTN inch tapered roller bearings — cone HM89446 and cup HM89410 delivered as a matched, separable pair of 34.925 mm bore and 76.2 mm outside diameter. The 4T prefix is NTN's tapered roller quality mark stamped on both parts; it is a brand mark, not a size code, so cross-references quote HM89446/HM89410 without it. Speed planning uses both catalogue columns: grease 5,100 r/min is the mechanical ceiling for 4T-HM89446/HM89410, oil 6,800 r/min with circulating oil — a 1,700 r/min margin at this size. The printed 86.5/105 kN ratings belong to the assembled HM89446+HM89410 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. A single-row tapered bearing reacts thrust in one direction only; 4T-HM89446/HM89410 is adjusted against a second bearing so the shaft is located in both directions.
Typical equipment & failure modes
Common applications
- industrial gearboxes built to inch shafting
- construction-equipment pivot and wheel positions
- mining and quarry conveyor drive pulleys
- machine-tool headstocks on inch spindles
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
- water-induced pitting when the open bearing sees washdown without external seals
Selection pitfalls — read before you substitute
- Hub and pinion positions of this 34.925 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-HM89446/HM89410.
- The heavy-medium HM family is proportioned for a high thrust share; swapping to a lighter LM or pure-numeric series at the same 34.925 mm bore cuts axial capacity even when the envelope fits — re-verify the load split before downgrading.
- Fit selection follows the rotating ring: a rotating cone on a 34.925 mm shaft takes a k5/m5 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- Do not confuse T (29.37 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- Inch and metric bores collide on paper — 34.925 mm is 1.375 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
- The 86.5/105 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-HM89446/HM89410; 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-HM89446/HM89410?
4T-HM89446/HM89410 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 34.925 mm bore (1.375 in), 76.2 mm outside diameter and 29.37 mm assembled width T (3 × 1.156 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 86.5 kN, C0 105 kN, grease limiting speed 5,100 r/min, oil speed 6,800 r/min, mass about 646 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-HM89446/HM89410 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the HM89446 cone or the HM89410 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 86.5/105 kN ratings change with the cup.
What is the difference between 4T-HM89446/HM89410 and a metric ISO 355 tapered bearing?
4T-HM89446/HM89410 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 34.925×76.2×29.37 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-HM89446/HM89410 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 HM89446/HM89410 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-HM89446/HM89410 list two speeds, 5,100 and 6,800 r/min?
The lower figure, 5,100 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-HM89446/HM89410 at 6,800 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.