HM212049-011 bearing: complete specifications & equivalents
The HM212049-011 is a ISO 355 radial bearing sized 65.088 x 122.238 x 38.1 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 65.088 mm |
| Outer diameter D | 122.238 mm |
| Width B | 38.1 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 229 kN |
| Basic static load rating C0 | 245 kN |
| Fatigue load limit Pu | 28 kN |
| Reference speed (thermal) | 4500 rpm |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1850 g |
| Manufacturer designation | SKF HM 212049/011 |
| 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 & HM212000-series range
| Bore d | 2.563 in |
|---|---|
| Outer diameter D | 4.813 in |
| Width B | 1.5 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 28.6 mm |
| Smallest bore in HM212000-series | 65.088 mm |
| Largest outer diameter in HM212000-series | 122.238 mm |
| Width range across HM212000-series | 38.1–38.1 mm |
| Bore position in HM212000-series (smallest first) | 1 of 1 |
| Bore above smallest HM212000-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HM212049-HM212010 | NTN | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
| HM212049-011 | 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 HM212049-011 model number is decoded
From a specification standpoint the 011 cup is the controlling half of HM212049 for housing design — it sets the 122.238 mm OD and the outer abutment diameter — while the HM 212049 cone controls shaft fit at the 65.088 mm bore; the 38.1 mm width is the result of the two together.SKF HM 212049/011 belongs to the SKF single-row tapered roller range — the 65.088 mm bore entry in the inch HM212000-series, dimensioned 122.238 mm OD and 38.1 mm wide.The HM212000-series series assigns 65.088 mm bore, 122.238 mm OD and 38.1 mm width to HM212049; the cone and cup references are not interchangeable with other inch-series pairs even when the bore matches, because the cup profile and rib geometry are series-specific. In SKF suffix language a bare HM212049 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. The 28 kN Pu figure feeds the adjusted-life equation at contaminated or partial-film conditions, and the 1.07 C0/C balance shows this execution is tuned to thrust-heavy combined loads rather than pure radial running. Because the contact line is tapered, one HM212049 reacts thrust in a single direction; bidirectional shafts need an O or X pair, and a rotating cone on a 65.088 mm shaft typically takes a k5 seat with an H7 housing bore. Dimensional interchange map: within the HM200 series at 65.088 mm bore, the 122.238 mm OD and 38.1 mm width are fixed by the ISO 355 plan, so any same-code bearing from another brand shares the mounting envelope; the 28.6 mm section height distinguishes this family from a 302 or 322 of the same bore, and the 1850 g mass is the minimum—sealed or snap-ring executions add rotating weight above that catalogue baseline.
Typical equipment & failure modes
Common applications
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- paper-machine and printing rolls
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
- roller large-end smearing against the cone rib after EP lubricant film failure
- 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
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Mount the 65.088 mm bore HM212049 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
- The HM212000-series inch series at 65.088 mm bore (122.238×38.1 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.
- O (back-to-back) pairs are stiffer against moments, X (face-to-face) pairs tolerate misalignment and thermal growth better; choosing the arrangement from the 2D drawing rather than the actual shaft thermal expansion is a common HM212049 mounting error.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of HM212049 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- Catalogue reference speed and limiting speed are different limits: the 4,500 r/min reference is a thermal criterion under load, while the 5,300 r/min limiting value is the mechanical ceiling — observe both.
- The 229/245 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 HM212049 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF HM 212049/011 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
Is HM212049 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 HM212049?
The SKF HM 212049/011 is a single-row tapered roller bearing with 65.088 mm bore, 122.238 mm outer diameter and 38.1 mm width (2.563 × 4.813 × 1.5 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 229 kN, C0 245 kN, fatigue load limit Pu 28 kN, reference speed 4,500 r/min, limiting speed 5,300 r/min, mass about 1850 g. It is an open, separable bearing with a pressed-steel cage.
How does the HM212049 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 HM212000-series code marks the dimensional series. The metric dimensions 65.088×122.238×38.1 mm are the converted equivalents of the original inch boundary dimensions.
What do the cone and cup numbers in HM212049 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 (HM212000-series) groups sizes that share the same boundary-dimension plan.
Can a single HM212049 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
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.