Deep-Groove Ball Bearings
General-purpose radial bearings with deep raceway grooves. They are widely used in motors, fans, pumps, gearboxes, conveyors, appliances, and industrial rotating equipment.
BEAR / BALL — ROTARY BEARING REFERENCE
Ball Bearings.
Ball bearings use rolling elements positioned between inner and outer races to reduce friction while supporting rotating shafts, wheels, spindles, motors, gearboxes, rollers, and other moving machine components. Bearing suitability depends on load direction, shaft and housing dimensions, speed, internal clearance, lubrication, sealing, alignment, temperature, contamination, mounting, and expected service life.
OPERATING PRINCIPLE
Rolling contact reduces friction between moving surfaces.
In a conventional ball bearing, hardened balls roll between raceways formed in the inner and outer rings. The balls support the relative motion of the rings while a cage or separator maintains spacing between the rolling elements.
Because the rolling elements contact the raceways over relatively small areas, ball bearings are well suited to applications requiring efficient rotation and comparatively high operating speeds.
Bearing geometry determines how radial and axial forces pass through the rolling elements, which is why two bearings with similar outside dimensions may still have very different load and speed capabilities.
BASIC BEARING IDENTIFICATION
Bore
Inside diameter that interfaces with the shaft.
Outside Ø
Outer-ring diameter that fits the housing.
Width
Axial envelope dimension of the bearing assembly.
Clearance
Internal movement available before installation and loading.
Load
Static and dynamic load capability for the design.
Speed
Operating-speed capability under specified conditions.
SECTION / 01
Common Ball Bearing Types
Raceway geometry, ball arrangement, contact angle, number of rows, seals, shields, and internal construction determine how a ball bearing responds to load and speed.
Angular Contact Bearings
Bearings designed with a defined contact angle that improves axial-load capability. They are often used where radial and thrust loads occur together.
Thrust Ball Bearings
Bearings intended primarily to support axial forces along the shaft centerline rather than conventional radial loading.
Self-Aligning Ball Bearings
Designs that can accommodate limited angular misalignment between the shaft and housing while continuing to support rotational motion.
Double-Row Ball Bearings
Bearings incorporating two rows of rolling elements to increase load capability, stiffness, or combined-load performance within a compact assembly.
Miniature Ball Bearings
Small precision bearings used in instruments, miniature motors, electronics, medical equipment, robotics, and other compact rotating assemblies.
Sealed Ball Bearings
Bearings incorporating contacting or near-contact seals to retain lubricant and limit entry of dust, moisture, or contaminants.
Shielded Ball Bearings
Bearings using non-contact shields that provide contamination protection while generally producing less drag than contacting sealing systems.
Linear Ball Bearings
Ball-based bearing assemblies adapted for straight-line motion, typically operating on shafts, guides, or rails rather than rotating around a fixed shaft.
LOAD / DIRECTION
Load direction determines bearing geometry.
The bearing must transmit applied forces through the rolling elements and raceways without excessive stress, deformation, heat, or fatigue.
BALL BEARING LOAD REFERENCE
Radial Load
Force acting generally perpendicular to the shaft axis.
Common in motors, pulleys, fans, and rotating shafts.
Axial Load
Force acting parallel to the shaft axis. Bearing geometry
determines the amount and direction of thrust that can
be accommodated.
Combined Load
Simultaneous radial and axial loading requiring a bearing
designed for the resulting force relationship.
Static Load
Load applied when the bearing is stationary or moving
very slowly, where permanent deformation can become
an important limitation.
Dynamic Load
Operating load associated with rotating service and
fatigue-based bearing life.
Shock Load
Short-duration impact or transient loading that can exceed
steady-state operating forces and affect raceways,
balls, cages, and mounting fits.
SECTION / 02
Bearing Construction
A bearing is a coordinated assembly. Each internal component influences friction, load transfer, speed, alignment, lubrication, and service life.
Inner Ring
Fits around the shaft and contains the inner raceway. Shaft fit influences support, alignment, internal clearance, and resistance to ring movement.
Outer Ring
Fits within the housing and provides the outer raceway. Housing geometry and fit affect support, alignment, temperature behavior, and load distribution.
Rolling Elements
Precision balls transfer load between the raceways while allowing relative motion with rolling rather than predominantly sliding contact.
Cage
Separates and guides the balls to maintain spacing and control rolling-element movement during operation.
SECTION / 03
Ball Bearing Specifications
Replacement compatibility requires more than matching bore diameter. The complete dimensional and operating specification should be checked.
Specification
What to Verify
Why It Matters
Bore
Shaft diameter and required fit.
Determines shaft interface, mounting, and ring support.
Outside Diameter
Housing bore and available radial envelope.
Determines whether the outer ring fits the existing housing.
Width
Axial bearing dimension and shoulder spacing.
Affects shaft position, retention, preload, and assembly clearance.
Load Rating
Static and dynamic load capabilities.
Determines suitability for applied loads and expected service life.
Clearance
Internal radial or axial clearance classification.
Mounting fits and operating temperature can reduce internal clearance.
Speed
Rotational speed and lubrication conditions.
Excess speed can increase heat, lubricant stress, and cage loading.
Seal / Shield
Open, sealed, shielded, or application-specific closure.
Influences contamination protection, lubricant retention, and friction.
Lubrication
Grease or oil type, quantity, viscosity, and service interval.
Lubrication controls friction, heat, wear, and surface protection.
Environment
Temperature, moisture, chemicals, particles, and washdown.
Environment affects materials, seals, lubricant, and expected life.
SECTION / 04
Ball Bearing Selection
Bearing selection begins with the machine requirements and then narrows the design by load, speed, dimensions, mounting, environment, lubrication, and life.
01
Define the Motion
Establish rotational speed, duty cycle, direction,
acceleration, required precision, noise constraints,
and whether motion is continuous or intermittent.
02
Determine Loads
Identify radial, axial, combined, static, dynamic,
shock, and moment-related forces acting through
the bearing arrangement.
03
Match Dimensions
Confirm bore, outside diameter, width, shoulders,
shaft geometry, housing geometry, retaining features,
and available installation space.
04
Select Bearing Type
Choose the raceway geometry and arrangement needed for
radial load, thrust load, combined loading, alignment,
stiffness, precision, and speed.
05
Evaluate Environment
Consider contamination, moisture, chemicals, operating
temperature, cleaning processes, corrosion, electrical
conditions, and lubricant compatibility.
06
Verify Installation
Confirm shaft and housing fits, internal clearance,
preload where applicable, mounting method, alignment,
lubrication, sealing, and maintenance access.
Compatibility / Note 04
Matching dimensions do not guarantee equal performance.
Two ball bearings can share the same bore, outside diameter, and width while differing in internal geometry, clearance, sealing, cage design, load rating, speed capability, material, lubrication, or precision class. Replacement bearings should therefore be compared against both the physical envelope and operating specification. See the Bearing & Bushing Selection Guide and Component Compatibility Guide before approving a substitution.
SECTION / 05
Bearing & Motion Resources
Additional industrial references for linear bearings, ball-based linear motion, slide bearings, and related guided-motion systems.
Linear Bearings
Broader industry resource covering bearing systems designed for controlled straight-line motion along shafts, rails, and guides.
Research Linear BearingsLinear Ball Bearings
Supporting reference for linear bearing assemblies that use rolling balls to reduce friction while guiding straight-line motion.
Research Linear Ball BearingsSlide Bearings
Reference information covering sliding bearing and guide arrangements used where plain-contact motion is preferred over rolling elements.
Research Slide BearingsLinear Slides
Related industrial resource covering guided linear slide assemblies used in positioning, automation, machinery, and precision motion applications.
Research Linear SlidesBearings & Bushings
Return to the main OpenType reference for rolling bearings, plain bearings, bushings, shaft support, friction, loads, and motion.
Bearing ReferenceBearing Selection Guide
Compare bearing and bushing options using load, speed, alignment, lubrication, fit, environment, and maintenance requirements.
Selection Guide
Reference note:
External resources are provided for additional research and
do not establish product compatibility, interchangeability,
certification, approval, or endorsement. Verify bearing
dimensions, load ratings, internal clearance, speed,
lubrication, mounting fits, sealing, and operating conditions
before specifying or substituting a bearing.
RELATED / BEARINGS
Continue the Bearing Reference
Compare rotary ball bearings with linear bearing systems, bushings, and the broader bearing-selection process.