Linear ball bearings are frequently used where high positional accuracy and high efficiency are a priority. The bearings must therefore run without stick-slip and with only low friction.

Linear ball bearings KN-B, KNO-B,KS, KSO, KB, KBS, KBO have particularly low friction.

The total friction consists of:

• rolling and sliding friction in rolling contacts
  (sliding friction in linear plain bearings)
• friction in the return zones and recirculation guides
• lubricant friction
• seal friction.

The factors on which the coefficient of friction depends may act in a reciprocal manner, may act in a single direction or may counteract each other.

The coefficients of friction for unsealed linear bearings with oil lubrication are given in the table.

In Permaglide^® linear plain bearings, the coefficient of friction is between 0,02 and 0,2.