Ball Bearing

The hardened balls are held between inner and outer races.
They are ideal for heavy-duty applications where ease of movement is a prime concern.
Bearings are pre-greased and sealed to prevent loss lubrication and to exclude dirt and grit.

Roller Bearing

These bearings have steel rollers fitted into steel or plastic housings.
They improve rolling resistance with light to medium loads.
Bearings are pre-greased and there is require no further lubrication unless used with heavy loads.

Plain Bearing

This is the simplest form of bearing with a plain hub.
They are normally used in castors for light duties at slow speeds and short distances.
They are impact and corrosion-resistant and require very little maintenance, apart from occasional lubrication.

Tapered Roller Bearing

These are the most robust of bearings and are used for very heavy duty applications.
Two bearings are mounted on either end of the axle.
The friction coefficient is higher than that of ball or roller bearings.
They require periodic lubrication.