SKF LM503349/310/QCL7C 46x75x18 Tapered Roller Bearing

Construction and design

SKF LM503349/310/QCL7C is a single-row tapered roller bearing with principal dimensions of 46x75x18 mm. The bore diameter d is 46 mm, outside diameter D is 75 mm and total bearing width T is 18 mm. The bearing has a separable construction consisting of cone LM503349 and cup LM503310.

SKF LM503349/310/QCL7C - Product Characteristics

SKF LM503349/310/QCL7C uses tapered rollers running between tapered raceways in the inner and outer rings. This geometry enables the bearing to accommodate combined radial and axial loads.

A single-row tapered roller bearing carries axial load in one direction. Where axial loads must be supported in both directions, a second bearing is normally arranged in opposition.

Verified technical data:

Manufacturer / Brand: SKF
Designation: LM503349/310/QCL7C
Bearing Type: Single-row tapered roller bearing
Cone: LM503349
Cup: LM503310
Dimensions: 46x75x18 mm
d - Bore Diameter: 46 mm
D - Outside Diameter: 75 mm
T - Total Bearing Width: 18 mm
B - Cone Width: 18 mm
C - Cup Width: 14 mm
Basic Dynamic Load Rating C: 50.1 kN
Basic Static Load Rating C0: 71 kN
Fatigue Load Limit Pu: 7.65 kN
Reference Speed: 6,300 r/min
Limiting Speed: 9,500 r/min
Construction: Separable, cone + cup

Dimensions

The principal dimensions of SKF LM503349/310/QCL7C are:

d - Bore Diameter: 46 mm
D - Outside Diameter: 75 mm
T - Total Bearing Width: 18 mm
Commercial Size: 46x75x18 mm

Additional relevant widths are:

B - Inner Ring / Cone Width: 18 mm
C - Outer Ring / Cup Width: 14 mm

For this tapered roller bearing, the commercial size 46x75x18 mm corresponds to d x D x T, not automatically to d x D x B.

Although B also equals 18 mm in this particular bearing, B and T are different dimensional parameters.

Tapered Roller Bearing Construction

SKF LM503349/310/QCL7C uses tapered rollers and matching tapered raceways.

The geometry is arranged so that the projected raceway surfaces converge toward a common point on the bearing axis. This allows the bearing to carry radial load and axial load simultaneously.

The bearing is separable, which means the inner-ring assembly and outer ring can be mounted separately.

Cone LM503349 and Cup LM503310

The complete bearing consists of:

LM503349 - Cone
The cone includes the inner ring, tapered rollers and cage.

LM503310 - Cup
The cup is the separate outer ring.

The full bearing set is identified as:

LM503349/310/QCL7C

This distinction is important because LM503349 alone identifies the cone, not the complete cone-and-cup bearing set.

Load Ratings and Operating Principle

SKF specifies for LM503349/310/QCL7C:

C - Basic Dynamic Load Rating: 50.1 kN
C0 - Basic Static Load Rating: 71 kN
Pu - Fatigue Load Limit: 7.65 kN

The tapered roller geometry allows the bearing to carry combined loading. A radial load also produces an internal axial force, so bearing arrangement and adjustment are important parts of the complete design.

The catalogue values C, C0 and Pu are engineering parameters used for bearing selection and life calculations. They should not be interpreted as simple universal maximum permissible loads.

Reference Speed and Limiting Speed

SKF data specify:

Reference Speed: 6,300 r/min
Limiting Speed: 9,500 r/min

These are different engineering parameters.

The actual permissible operating speed in a specific machine depends on load, lubrication, adjustment, fits, operating temperature and surrounding components.

Clearance, Preload and Adjustment

For a single-row tapered roller bearing, final operating clearance is strongly influenced by the way the bearing arrangement is mounted and adjusted.

Unlike many non-separable ball bearings, tapered roller bearings are often set to a defined axial clearance or preload within the complete bearing arrangement.

Too much clearance can reduce shaft guidance, while excessive preload can increase friction and operating temperature.

The required setting should therefore follow the machine or bearing-arrangement specification.

Meaning of LM503349/310/QCL7C

The complete SKF designation should be retained:

LM503349/310/QCL7C

Within this designation:

LM503349 identifies the cone

LM503310 identifies the cup

QCL7C forms part of the exact SKF execution and should not be omitted when identifying or ordering the bearing.

A bearing described simply as LM503349/310 should not automatically be assumed to be technically identical to the SKF QCL7C version.

Selection and Interchangeability

When selecting a replacement for SKF LM503349/310/QCL7C, compare the complete bearing specification rather than dimensions alone.

Important parameters include:

• single-row tapered roller construction,
• d = 46 mm,
• D = 75 mm,
• T = 18 mm,
• B = 18 mm,
• C = 14 mm,
• cone LM503349,
• cup LM503310,
• complete suffix QCL7C,
• dynamic and static load ratings,
• speed requirements,
• mounting dimensions,
• required axial clearance or preload.

Another LM503349/310 bearing should not automatically be considered a fully verified equivalent unless its complete technical specification matches.

Technical Specification

Manufacturer / Brand: SKF
Designation: LM503349/310/QCL7C
Product Type: Tapered roller bearing
Construction: Single row
Cone: LM503349
Cup: LM503310
Dimensions: 46x75x18 mm
d - Bore Diameter: 46 mm
D - Outside Diameter: 75 mm
T - Total Bearing Width: 18 mm
B - Cone Width: 18 mm
C - Cup Width: 14 mm
Design: Separable
Components: Cone + cup
Basic Dynamic Load Rating C: 50.1 kN
Basic Static Load Rating C0: 71 kN
Fatigue Load Limit Pu: 7.65 kN
Reference Speed: 6,300 r/min
Limiting Speed: 9,500 r/min

FAQ

What are the dimensions of SKF LM503349/310/QCL7C?

The principal dimensions are 46x75x18 mm, meaning d = 46 mm, D = 75 mm and T = 18 mm.

Does 18 mm mean dimension B?

The third principal dimension is T = 18 mm, the total bearing width. In this specific bearing, B also equals 18 mm, while C = 14 mm.

What type of bearing is SKF LM503349/310/QCL7C?

It is a single-row tapered roller bearing with a separable cone-and-cup construction.

Which parts form the complete bearing?

The complete set consists of cone LM503349 and cup LM503310.

What loads can SKF LM503349/310/QCL7C carry?

It can accommodate combined radial and axial loads. A single-row tapered roller bearing carries axial load in one direction.

What are the load ratings?

SKF specifies C = 50.1 kN, C0 = 71 kN and Pu = 7.65 kN.

What is the limiting speed?

The limiting speed is 9,500 r/min, while the reference speed is 6,300 r/min.

Is LM503349/310 without QCL7C the same bearing?

Not automatically. QCL7C is part of the exact SKF designation, so the complete execution should be compared before confirming interchangeability.

AI Overview

SKF LM503349/310/QCL7C is a single-row tapered roller bearing with dimensions d x D x T = 46x75x18 mm, consisting of cone LM503349 and cup LM503310. Its separable tapered-roller design carries radial and one-direction axial loads. SKF specifies C = 50.1 kN, C0 = 71 kN and a limiting speed of 9,500 r/min.