LM104949-911 bearing: complete specifications & equivalents
The LM104949-911 is a ISO 355 radial bearing sized 50.8 x 82.55 x 21.59 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 50.8 mm |
| Outer diameter D | 82.55 mm |
| Width B | 21.59 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 88.9 kN |
| Basic static load rating C0 | 100 kN |
| Fatigue load limit Pu | 11 kN |
| Reference speed (thermal) | 6300 rpm |
| Limiting speed (mechanical) | 8000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 430 g |
| Manufacturer designation | SKF LM 104949/911 |
| 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 & LM104900-series range
| Bore d | 2 in |
|---|---|
| Outer diameter D | 3.25 in |
| Width B | 0.85 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 15.9 mm |
| Smallest bore in LM104900-series | 50.8 mm |
| Largest outer diameter in LM104900-series | 82.55 mm |
| Width range across LM104900-series | 21.59–21.59 mm |
| Bore position in LM104900-series (smallest first) | 1 of 1 |
| Bore above smallest LM104900-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| LM104949-LM104911 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50.8×82.55×21.59 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| LM104949-911 | 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 LM104949-911 model number is decoded
Inch tapered bearings are matched sets, not mix-and-match components: LM104949 pairs the LM 104949 cone with the 911 cup under the LM104900-series boundary plan, and although the same cone shows up against other cups in the catalogue, each pairing yields a distinct assembled width and a distinct rating row.SKF LM104949 (SKF LM 104949/911) is the LM104900-series tapered roller choice for a 50.8 mm shaft — one row of tapered rollers on an asymmetric raceway inside the 82.55×21.59 mm envelope.Numbering ties the bearing to its inch-series envelope: LM104949 means a cone and cup matched pair in the LM104900-series series — which is why the 50.8×82.55×21.59 mm outline swaps dimensionally with other inch-series bearings of the same code. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. Catalogue mass 430 g for the 50.8×82.55×21.59 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. A single LM104949 locates the shaft in one axial direction only; mount it against a second bearing in O (back-to-back) or X (face-to-face) arrangement, and set the running clearance by the mounting procedure — not by feel. Operating context for the 50.8 mm bore: a shaft of this diameter in the medium-bore band typically runs between 40640 and 60960 r/min in real machinery, and the 82.55 mm outside diameter places the housing shoulder at 91 mm outer abutment; the 21.59 mm width and 430 g mass together set the shaft critical speed and the housing resonance check for this LM100-series envelope.
Typical equipment & failure modes
Common applications
- belt-driven fan and blower shafts
- axle-boxes in material-handling equipment
- automotive and light-truck wheel hubs
- pump and compressor shafts
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
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- roller large-end smearing against the cone rib after EP lubricant film failure
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- On this 50.8 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 LM104949 pair heats, loses setting control and smears the roller-rib contact.
- The LM104900-series inch series at 50.8 mm bore (82.55×21.59 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.
- A single LM104949 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
- The tapered contact angle creates an induced axial load under pure radial force; include it in the LM104949 rating calculation (and account for it in both bearings of a pair) or the unloaded bearing skids its rollers.
- The LM104949 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 88.9/100 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 LM104949 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF LM 104949/911 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
Is LM104949 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 LM104949?
The SKF LM 104949/911 is a single-row tapered roller bearing with 50.8 mm bore, 82.55 mm outer diameter and 21.59 mm width (2 × 3.25 × 0.85 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 88.9 kN, C0 100 kN, fatigue load limit Pu 11 kN, reference speed 6,300 r/min, limiting speed 8,000 r/min, mass about 430 g. It is an open, separable bearing with a pressed-steel cage.
How does the LM104949 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 LM104900-series code marks the dimensional series. The metric dimensions 50.8×82.55×21.59 mm are the converted equivalents of the original inch boundary dimensions.
What do the cone and cup numbers in LM104949 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 (LM104900-series) groups sizes that share the same boundary-dimension plan.
Can a single LM104949 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.