The contact bushes are usually made of metal and are lubrication and maintenance free. They may be made of sheet metal lined with anti-friction material or made entirely of plastic and their radial size is minimal. Some versions are lead-free or designed for use in the food processing and pharmaceutical industries.The lining or the actual material with which they are made aids smooth running.
The main advantage of the bushes is that of guaranteeing smooth running with reduced friction, in addition to the fact that they are more or less silent. Resistance to vibrations and their lift in relation to the supporting surface are also good, in addition to their resistance to dust. They are generally used in rotary motion systems or for linear movements, from very short to short.