HM911245-HM911210 bearing: complete specifications & equivalents
The HM911245-HM911210 is a ANSI ABMA 19.2 radial bearing sized 60.325 x 130.175 x 36.512 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 60.325 mm |
| Outer diameter D | 130.175 mm |
| Width B | 36.512 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 173 kN |
| Basic static load rating C0 | 186 kN |
| Limiting speed (mechanical) | 2700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2120 g |
| Manufacturer designation | NTN 4T-HM911245/HM911210 |
| 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 | 2.375 in |
|---|---|
| Outer diameter D | 5.125 in |
| Width B | 1.437 in |
| ISO bore code | 45 |
| Radial section height (D−d)/2 | 34.9 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) | 77 of 148 |
| Bore above smallest 4t-inch-series size | 47.625 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HM911245-210 | 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 HM911245-HM911210 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-HM911245/HM911210 denotes the heavy-medium HM family of NTN inch tapered roller bearings — cone HM911245 and cup HM911210 delivered as a matched, separable pair of 60.325 mm bore and 130.175 mm outside diameter. Reading the designation: 4T-HM911245/HM911210 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 heavy-medium HM family lettering ties the pair to its boundary plan. Grease relubrication at the 2,700 r/min limiting speed targets the cone-rib contact; sustaining 3,600 r/min needs an oil supply directed at the large roller ends. Housing fitment sequence for 4T-HM911245/HM911210: press the HM911210 cup square into the 130.175 mm seat first, then bring the HM911245 cone (on its 60.325 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. Mount the 60.325 mm cone with an induction heater (max 120 °C) and press the 130.175 mm cup with a sleeve; driving either ring through the rollers brinells the raceways.
Typical equipment & failure modes
Common applications
- marine winch and deck-machinery shafts
- crusher and screening-plant eccentric shafts
- heavy truck and bus drive-axle differentials
- plant gearboxes on inch-dimensioned shaft lines
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
- edge loading when shaft deflection exceeds the few arc-minutes an adjusted pair tolerates
Selection pitfalls — read before you substitute
- Mount the 60.325 mm cone by induction heating (max 120 °C) and the 130.175 mm cup with a press sleeve; at 2120 g a cocked ring brinells the raceway directly.
- The heavy-medium HM family is proportioned for a high thrust share; swapping to a lighter LM or pure-numeric series at the same 60.325 mm bore cuts axial capacity even when the envelope fits — re-verify the load split before downgrading.
- An unloaded 4T-HM911245/HM911210 near 2,700 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded high-speed pairs.
- Shaft and housing fillets must clear the ring chamfers of HM911245 and HM911210; use undercut shoulders so the rings seat on the face, not on a radius.
- Never drive the 130.175 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 173/186 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-HM911245/HM911210; 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-HM911245/HM911210?
4T-HM911245/HM911210 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 60.325 mm bore (2.375 in), 130.175 mm outside diameter and 36.512 mm assembled width T (5.125 × 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 173 kN, C0 186 kN, grease limiting speed 2,700 r/min, oil speed 3,600 r/min, mass about 2120 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-HM911245/HM911210 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the HM911245 cone or the HM911210 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 173/186 kN ratings change with the cup.
What is the difference between 4T-HM911245/HM911210 and a metric ISO 355 tapered bearing?
4T-HM911245/HM911210 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 60.325×130.175×36.512 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-HM911245/HM911210 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 HM911245/HM911210 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-HM911245/HM911210 list two speeds, 2,700 and 3,600 r/min?
The lower figure, 2,700 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-HM911245/HM911210 at 3,600 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.