- Ball bearings, like all bearings, work because rolling is the most efficient form of movement for an inanimate object. Rolling produces less friction than sliding, so things that roll don't wear out as fast.
- Basically, a ball bearing system places small smooth spheres between two other smooth surfaces. An inline skate wheel, for example, has a smooth inner ring and a larger smooth outer ring with small balls in between, the balls 'bear the load' and allow the two rings to rotate with a minimum of friction, creating fast, efficient movement.
- Ball bearings have very little surface contact, and therefore produce the minimum amount of friction. Ball bearings spin very smoothly. They can be used with both radial and thrust loading. Radial loading puts the pressure on sides of the bearing (like a pulley) and thrust loads are direct weight (like a spinning barstool).
- The main disadvantage of ball bearings is that they cannot usually handle a lot of weight for their size. Because of the small contact area, they have a tendency to squish or deform when they are placed under too much pressure. Some types of ball bearings are also noisy.
- Deep groove ball bearings are used a lot for high-speed applications such as inside motors. They can withstand high radial force for sustained periods. Shielded and sealed ball bearings are designed for use in dusty or dirty environments, the shield or seal protects the bearing, keeping grease in and foreign particles out.
