HM88542-HM88510 bearing: complete specifications & equivalents
The HM88542-HM88510 is a ANSI ABMA 19.2 radial bearing sized 31.75 x 73.025 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 | 31.75 mm |
| Outer diameter D | 73.025 mm |
| Width B | 29.37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 80 kN |
| Basic static load rating C0 | 97 kN |
| Limiting speed (mechanical) | 5400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 622 g |
| Manufacturer designation | NTN 4T-HM88542/HM88510 |
| 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 | 1.25 in |
|---|---|
| Outer diameter D | 2.875 in |
| Width B | 1.156 in |
| ISO bore code | 42 |
| 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) | 32 of 148 |
| Bore above smallest 4t-inch-series size | 19.05 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HM88542-HM88512 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN cone 4T-HM88542 paired with a different cup (HM88512): cone interchangeable, cup differs — OD, assembled width T and ratings follow the cup. Verify the full cone/cup reference before substituting. |
| HM88542-510 | 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 HM88542-HM88510 model number is decoded
4T-HM88542/HM88510 belongs to the NTN inch 4T tapered roller range (heavy-medium HM family); cone and cup are ordered by their own references and are individually interchangeable with like-numbered parts. Unlike ISO 355 metric numbers, this ABMA code does not encode the bore arithmetically: HM88542 identifies the cone of 31.75 mm (1.25 in) bore by catalogue lookup, and HM88510 fixes the 73.025 mm OD. Contact-angle geometry of the heavy-medium HM family gives 4T-HM88542/HM88510 its radial/axial load split — at 80/97 kN the static rating is about 1.21× C, typical of inch tapered sets proportioned for combined duty. The printed 80/97 kN ratings belong to the assembled HM88542+HM88510 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. Mount the 31.75 mm cone with an induction heater (max 120 °C) and press the 73.025 mm cup with a sleeve; driving either ring through the rollers brinells the raceways.
Typical equipment & failure modes
Common applications
- pump and blower drive shafts with combined load
- truck and trailer axle hubs on inch-dimensioned axles
- agricultural tractor transmission and PTO shafts
- industrial gearboxes built to inch shafting
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- 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 31.75 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-HM88542/HM88510.
- The heavy-medium HM family is proportioned for a high thrust share; swapping to a lighter LM or pure-numeric series at the same 31.75 mm bore cuts axial capacity even when the envelope fits — re-verify the load split before downgrading.
- Never drive the 73.025 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.
- Never drive the 73.025 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.
- Open 4T-HM88542/HM88510 sets have no seals: a hub or gearbox needs external sealing or the 5,400 r/min grease figure is meaningless once water reaches the cone rib.
- The 80/97 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-HM88542/HM88510; 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-HM88542/HM88510?
4T-HM88542/HM88510 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 31.75 mm bore (1.25 in), 73.025 mm outside diameter and 29.37 mm assembled width T (2.875 × 1.156 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 80 kN, C0 97 kN, grease limiting speed 5,400 r/min, oil speed 7,100 r/min, mass about 622 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-HM88542/HM88510 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the HM88542 cone or the HM88510 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 80/97 kN ratings change with the cup.
What is the difference between 4T-HM88542/HM88510 and a metric ISO 355 tapered bearing?
4T-HM88542/HM88510 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 31.75×73.025×29.37 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-HM88542/HM88510 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 HM88542/HM88510 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-HM88542/HM88510 list two speeds, 5,400 and 7,100 r/min?
The lower figure, 5,400 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-HM88542/HM88510 at 7,100 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.