This Resource Centre provides general guidance only. Always follow the equipment manufacturer’s instructions, the product technical data sheet and your site’s safe system of work. Isolate stored energy before maintenance. For safety-critical, regulated or uncertain applications, ask a competent engineer or the product manufacturer to confirm the specification.
Bearing selection begins with the operating conditions, not the catalogue number. Start by defining what the bearing must carry, how fast it will run and what could disturb it.
Load direction and magnitude
Radial load acts across the shaft. Axial or thrust load acts along it. Some bearings are optimised for one direction; others carry a combination.
- Deep-groove ball bearings suit many moderate-load, higher-speed duties.
- Cylindrical roller bearings provide strong radial capacity.
- Tapered roller and angular-contact bearings suit combined load where axial control matters.
- Spherical roller bearings suit heavy-duty applications affected by deflection or misalignment.
- Thrust bearings are selected principally for axial load and must not be assumed to carry significant radial load.
Shock, vibration and rapidly changing load require additional consideration. Use the manufacturer’s calculation method rather than selecting solely by physical size.
Speed, temperature and lubrication
Higher speed increases heat and places greater demands on cage design, internal clearance and lubricant. Temperature affects lubricant viscosity, seal material and the fit between components. Use both normal and peak values when assessing the application.
Alignment and stiffness
Misalignment can come from shaft deflection, housing inaccuracy or mounting error. A self-aligning bearing can tolerate some angular error, but it does not correct a badly machined or moving housing. Where shaft location and rigidity are important, a paired or adjusted bearing arrangement may be needed.
Environment
Water, abrasive dust, washdown chemicals and electrical current can shorten bearing life. Review:
- seal or shield arrangement;
- housing sealing;
- corrosion-resistant materials or coatings;
- lubricant compatibility;
- electrically insulated or hybrid designs for relevant motor applications.
Space and mounting
Available radial and axial space may determine the bearing family. Also consider how the bearing will be installed, adjusted and removed. A technically suitable bearing is a poor maintenance choice if it cannot be fitted without transmitting force through the rolling elements.
Final check
Confirm the full bearing designation, load rating, limiting speed, clearance, accuracy, cage, closure, lubrication and mounting requirements against the manufacturer’s current data. For critical machinery, ask a bearing application engineer to validate the selection.
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