LM603049-011AA bearing: complete specifications & equivalents
The LM603049-011AA is a ISO 355 radial bearing sized 45.242 x 77.788 x 19.842 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45.242 mm |
| Outer diameter D | 77.788 mm |
| Width B | 19.842 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 66.8 kN |
| Basic static load rating C0 | 69.5 kN |
| Fatigue load limit Pu | 7.65 kN |
| Reference speed (thermal) | 7000 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 370 g |
| Manufacturer designation | SKF LM 603049/011 AA |
| 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 & LM603000-series range
| Bore d | 1.781 in |
|---|---|
| Outer diameter D | 3.063 in |
| Width B | 0.781 in |
| ISO bore code | 49 |
| Radial section height (D−d)/2 | 16.3 mm |
| Smallest bore in LM603000-series | 45.242 mm |
| Largest outer diameter in LM603000-series | 77.788 mm |
| Width range across LM603000-series | 19.842–21.43 mm |
| Bore position in LM603000-series (smallest first) | 1 of 1 |
| Bore above smallest LM603000-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| LM603049-LM603011 | NTN | 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. |
| LM603049-011AA | 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 LM603049-011AA model number is decoded
In SKF suffix language a bare LM603049 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. At 7,000 r/min reference speed the 16.3 mm-section LM603049 is governed thermally by preload and lubricant flow; grease or oil selection should be made against that value, with 8,500 r/min as the mechanical ceiling. Fit selection follows the rotating ring — interference on a rotating cone — and two LM603049 units are required to take reversing thrust; keep the induced axial load inside the rated capacity when calculating the pair. Cross-section geometry: the 16.3 mm half-section ((77.788−45.242)/2) of this LM600-series unit places the roller large-end pitch diameter at roughly 61 mm, and the 19.842 mm axial width is split between cone (11 mm) and cup rib (9 mm) — a geometry that sets the contact angle and, with the 370 g rotating cone mass, the critical speed at which cage-roller imbalance begins. Why the cup reference matters here: in the LM603000-series tables the LM 603049 cone appears against several cup options. LM603049 is the pairing with 011 AA, and that choice — not the cone — fixes the 77.788 mm OD, the raceway track position and the 19.842 mm assembled width.In SKF catalogue PUB BU/P1 17000, LM603049 appears as SKF LM 603049/011 AA: an open, single-row tapered roller bearing in the LM603000-series, supplied with a pressed-steel cage as standard.Reading the designation: LM603049 follows the Timken-style inch convention — the cone (inner ring with rollers) and cup (outer ring) are quoted as a pair separated by a slash, and the LM603000-series code identifies the dimensional series. The 45.242 mm bore, 77.788 mm OD and 19.842 mm width are the metric equivalents of the inch boundary dimensions.
Typical equipment & failure modes
Common applications
- machine-tool spindles
- belt-driven fan and blower shafts
- axle-boxes in material-handling equipment
- industrial gearbox shafts and reducers
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
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- grease degradation after long shelf storage without rotation or re-greasing
Selection pitfalls — read before you substitute
- On this 45.242 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 LM603049 pair heats, loses setting control and smears the roller-rib contact.
- The LM603000-series inch series at 45.242 mm bore (77.788×19.842 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.
- Setting is a design value, not an assembly feel: excessive preload in the LM603049 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- Do not mix brands or executions inside one LM603049 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.
- The pressed-steel cage is rated for standard industrial service; sustained running above the limiting speed or with degraded lubricant wears the cage pockets — inspect the cage at every relubrication interval.
- The 66.8/69.5 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 LM603049 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF LM 603049/011 AA designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What do the cone and cup numbers in LM603049 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 (LM603000-series) groups sizes that share the same boundary-dimension plan.
Can a single LM603049 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.
How does LM603049 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load LM603049 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit LM603049?
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 19.842 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 LM603049 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.
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.