Bearing Types
Bearings fall into two broad families. Rolling-element bearings use balls or rollers between two rings to give very low friction; plain (fluid-film) bearings use a film of lubricant instead of rolling elements. Within the rolling family, each type is optimised for a different mix of load, speed and alignment. This reference covers the main types side by side.
Quick comparison
| Type | Radial load | Axial load | Speed | Tolerates misalignment |
|---|---|---|---|---|
| Deep-groove ball | Good | Moderate (both ways) | Very high | Little |
| Angular-contact ball | Good | High (one way) | Very high | Little |
| Self-aligning ball | Moderate | Low | High | Yes |
| Cylindrical roller | High | Low / none* | High | Little |
| Tapered roller | High | High (one way) | Moderate | Little |
| Spherical roller | Very high | Moderate | Moderate | Yes |
| Thrust | Low / none | Very high | Lower | Some types |
| Plain / fluid-film | Very high | Type-dependent | Wide range | Some types |
*Some cylindrical roller designs (NJ, NUP) locate the shaft axially in one or both directions.
Deep-groove ball bearings
The most common bearing of all — the default choice for general-purpose rotation. Balls run in deep grooves in both rings, giving low, almost point-contact friction.
- Construction
- Single row of balls in deep raceway grooves, held by a cage.
- Loads
- Radial and moderate axial load in both directions.
- Speed
- Very high; low friction, low noise.
- Typical uses
- Electric motors, pumps, gearboxes, fans, appliances — almost anywhere.
- Variants & designations
- 6xxx series; available open, shielded (Z / ZZ) or sealed (RS / 2RS). See shielded vs sealed.
Angular-contact ball bearings
Designed to carry a defined axial load in one direction as well as radial load, by setting the ball contact at an angle across the bearing.
- Construction
- Single row of balls with a contact angle (commonly 15°, 25° or 40°); raceway shoulders are higher on one side.
- Loads
- Combined radial and one-direction axial; the larger the contact angle, the more axial capacity.
- Speed
- Very high; widely used in precision spindles.
- Typical uses
- Machine-tool spindles, pumps, gearboxes — wherever axial location and high speed are both needed.
- Variants & designations
- 7xxx (single row), often mounted in pairs (back-to-back, face-to-face or tandem) and preloaded; double-row types also exist.
Self-aligning ball bearings
Built to keep running smoothly even when the shaft is slightly misaligned or deflects under load.
- Construction
- Two rows of balls sharing a common spherical raceway in the outer ring, so the inner ring and balls can swivel.
- Loads
- Moderate radial, low axial.
- Speed
- High.
- Typical uses
- Long or multi-bearing shafts prone to misalignment, textile and woodworking machinery, fans.
- Variants & designations
- 12xx / 13xx (and wider 22xx / 23xx); available on tapered bores with adapter sleeves.
Cylindrical roller bearings
Use line contact instead of point contact, so they carry much heavier radial loads than ball bearings of the same size.
- Construction
- One row of cylindrical rollers; flanges (ribs) on one or both rings determine whether the shaft is guided axially.
- Loads
- High radial. Most designs allow the shaft to move axially, which suits floating (non-locating) positions and thermal expansion; some designs (NJ, NUP) also locate the shaft.
- Speed
- High.
- Typical uses
- Large electric motors, gearboxes, axleboxes, rolling-mill stands.
- Variants & designations
- N, NU, NJ, NUP, NF (the letters describe the flange arrangement); full-complement versions carry very heavy loads at lower speed.
Tapered roller bearings
Carry heavy combined loads — radial and one-direction axial together — using tapered rollers whose contact lines meet at a common point on the axis.
- Construction
- Tapered rollers between tapered raceways; the cup (outer ring) separates from the cone (inner ring with rollers).
- Loads
- Heavy radial and heavy one-direction axial.
- Speed
- Moderate.
- Typical uses
- Automotive wheel hubs, axles, gearboxes, heavy machinery; four-row versions support rolling-mill roll necks.
- Variants & designations
- Mounted in opposing pairs with clearance or preload set at assembly; metric 3xxxx series (e.g. 30205) and inch series. See tapered roller vs ball.
Spherical roller bearings
Combine very high load capacity with self-alignment — the heavy-duty choice for tough, misaligning conditions.
- Construction
- Two rows of barrel-shaped rollers running on a common spherical raceway in the outer ring, so the bearing self-aligns.
- Loads
- Very high radial and moderate axial in both directions.
- Speed
- Moderate.
- Typical uses
- Vibrating screens, crushers, continuous casters, paper mills, fans and heavy industrial drives.
- Variants & designations
- 222xx / 223xx etc.; available on tapered bores with adapter sleeves.
Thrust bearings
Made specifically to carry axial (thrust) loads rather than radial ones.
- Construction
- Washers (races) with balls or rollers between them. Thrust ball bearings handle lighter axial loads; cylindrical and spherical roller thrust bearings handle heavier ones. Single- or double-direction.
- Loads
- High to very high axial; little or no radial capacity.
- Speed
- Lower than radial bearings.
- Typical uses
- Crane hooks, vertical pump and turntable shafts, gearbox thrust take-up, swivels.
- Variants & designations
- 5xxxx thrust ball; spherical roller thrust for combined heavy axial with some radial.
Fluid-film (plain / journal) bearings
The oldest bearing principle — no rolling elements at all. A film of lubricant separates the shaft from the bearing surface, giving quiet, vibration-free running and, when the film is maintained, almost unlimited life.
- Construction
- A bush, sleeve or set of pads around the shaft. The film may be self-generating with speed (hydrodynamic) or supplied under pressure (hydrostatic). Oil-film "Morgoil"-type bearings support rolling-mill back-up rolls.
- Loads
- Very high; excellent at absorbing shock and damping vibration.
- Speed
- From very slow heavy shafts to very high-speed turbines.
- Typical uses
- Steam and gas turbines, large compressors, engine crankshafts, rolling-mill back-up rolls, and large slow-moving heavy shafts.
- Materials
- White metal (babbitt), bronze or polymer bearing surfaces.
Plain bearings have no rolling-contact fatigue limit, but they depend entirely on the lubricant film — a loss of lubrication is rapidly destructive.
Special variants
Across these families you will also find: sealed and shielded versions (built-in protection — see shielded vs sealed); hybrid and full-ceramic bearings (ceramic rolling elements for high speed, low friction and electrical insulation); and insulated bearings for inverter-driven motors, which prevent the electrical erosion that stray currents cause.
Not sure which type or size you need? See All About Bearings for selection, the Standards Hub for designations and clearance, and the Bearing Search to compare dimensions across brands.