HM88649-610 bearing: complete specifications & equivalents
The HM88649-610 is a ISO 355 radial bearing sized 34.925 x 72.233 x 25.4 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 34.925 mm |
| Outer diameter D | 72.233 mm |
| Width B | 25.4 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 83 kN |
| Basic static load rating C0 | 90 kN |
| Fatigue load limit Pu | 10 kN |
| Reference speed (thermal) | 7500 rpm |
| Limiting speed (mechanical) | 9000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 500 g |
| Manufacturer designation | SKF HM 88649/610 |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB |
| Last verified | 2026-09-28 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB) · extracted 2026-09-28
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & HM88600-series range
| Bore d | 1.375 in |
|---|---|
| Outer diameter D | 2.844 in |
| Width B | 1 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 18.7 mm |
| Smallest bore in HM88600-series | 34.925 mm |
| Largest outer diameter in HM88600-series | 72.233 mm |
| Width range across HM88600-series | 25.4–25.4 mm |
| Bore position in HM88600-series (smallest first) | 1 of 2 |
| Bore above smallest HM88600-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HM88649-HM88610 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 34.925×72.233×25.4 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| HM88649-610 | Timken | full Dimensions and internal design equivalent — standard interchange. | Same inch-series cone/cup boundary envelope (d/D/T); load ratings and speed limits are brand-specific and may differ. |
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 HM88649-610 model number is decoded
Material and manufacturing detail: the 500 g catalogue mass reflects through-hardened bearing steel (density ~7.85 g/cm³) machined to the HM800 ISO envelope, with the pressed-steel cage contributing roughly 15 g of the total; the 34.925 mm bore is ground to IT5 roundness and the 72.233 mm OD to IT5 cylindricity, and the 25.4 mm width tolerance keeps the pair-setting scatter within the ISO preload class. Within the HM88600-series tables, HM 88649 appears in several rows because SKF lists multiple cup options for the same cone. HM88649 is the 610 variant, with 72.233 mm OD and 25.4 mm width; neighbouring rows on the same cone differ only in the cup but are separate orderable bearings.SKF HM 88649/610 belongs to the SKF single-row tapered roller range — the 34.925 mm bore entry in the inch HM88600-series, dimensioned 72.233 mm OD and 25.4 mm wide.Numbering ties the bearing to its inch-series envelope: HM88649 means a cone and cup matched pair in the HM88600-series series — which is why the 34.925×72.233×25.4 mm outline swaps dimensionally with other inch-series bearings of the same code. In SKF suffix language a bare HM88649 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. Catalogue mass 500 g for the 34.925×72.233×25.4 mm open execution covers the pressed-steel cage and standard roller complement; sealed or special-clearance variants differ slightly in mass and carry their own order numbers. For a 34.925 mm shaft the usual cone seat is k5 with an H7 housing when the inner ring rotates; arrange two HM88649 bearings as a set for two-direction location and set clearance from the load diagram, never from assembly feel.
Typical equipment & failure modes
Common applications
- axle-boxes in material-handling equipment
- automotive and light-truck wheel hubs
- industrial gearbox shafts and reducers
- differential and pinion drives
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- On this 34.925 mm bore, interference and temperature rise consume clearance inside a preloaded pair; calculate the residual clearance after mounting and at operating temperature — an over-tight HM88649 pair heats, loses setting control and smears the roller-rib contact.
- The HM88600-series inch series at 34.925 mm bore (72.233×25.4 mm) follows the Timken cone/cup convention; substitutions must match both the cone and cup reference exactly — interchanging with another series or a metric 3xxxx bearing of the same bore changes OD, width and contact angle, so re-run the pair setting and shoulder-diameter checks before swapping.
- Do not mix brands or executions inside one HM88649 pair — matched sets are ground for a specific setting, and pairing a SKF basic unit with a different suffix variant will not share the setting evenly.
- Setting is a design value, not an assembly feel: excessive preload in the HM88649 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- The HM88649 shares its ISO 355 envelope with other tapered bearings of the same code but is not a drop-in replacement for a ball bearing: it cannot run effectively under pure radial load without a minimum axial load, and a deep-groove bearing cannot replace its combined-load duty.
- The 83/90 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of HM88649 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF HM 88649/610 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What shaft and housing fits suit HM88649?
For a rotating shaft under normal load, seat the cone on a k5 shaft fit; the cup is usually a loose-to-transition fit in the housing so it can creep slightly and distribute wear. Chamfer and shoulder diameters must clear the bearing rings so the 25.4 mm-wide cup seats square; the mounting setting (end play or preload) is set by the axial position of the cup relative to the cone.
Is HM88649 interchangeable with other brands?
Inch-series tapered roller bearings follow a long-standing industry boundary plan, so cones and cups of the same basic number are generally dimensionally interchangeable across manufacturers. However, internal geometry, cage design and load ratings differ by brand, so for paired or precision applications keep both halves of the set from one manufacturer — or re-verify ratings and setting when mixing.
What are the dimensions and catalogue data of HM88649?
The SKF HM 88649/610 is a single-row tapered roller bearing with 34.925 mm bore, 72.233 mm outer diameter and 25.4 mm width (1.375 × 2.844 × 1 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 83 kN, C0 90 kN, fatigue load limit Pu 10 kN, reference speed 7,500 r/min, limiting speed 9,000 r/min, mass about 500 g. It is an open, separable bearing with a pressed-steel cage.
How does the HM88649 inch-series designation work?
Inch-series tapered roller bearings use a Timken-style cone/cup convention: the number before the slash identifies the cone (inner ring with roller and cage assembly), the number after the slash identifies the cup (outer ring), and the HM88600-series code marks the dimensional series. The metric dimensions 34.925×72.233×25.4 mm are the converted equivalents of the original inch boundary dimensions.
What do the cone and cup numbers in HM88649 mean?
The cone number (before the slash) identifies the inner ring, rollers and cage; the cup number (after the slash) identifies the outer ring. Both are quoted together because a single-row tapered roller bearing is a matched separable pair — the cone and cup are ground to work together and are not interchangeable with arbitrary other parts. The series prefix (HM88600-series) groups sizes that share the same boundary-dimension plan.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB on 2026-09-28. Read our editorial & correction policy.