3. Ancillary aspects

Guiding accuracy: this is expressed in 10 ^{– 4} D, i.e. for a 10 mm diameter shaft with a guiding accuracy of 1, the shaft's radial freedom of movement is 1 µm. Similarly, for a thrust bearing, it expresses axial play in 10 ^{– 4} D.

Ability to accept misalignment: due to construction principles or bending movements, some shafts may be misaligned in relation to the bearings.

While this aptitude for a spherical roller bearing or thrust bearing can be described as excellent, that of an aerostatic bearing operating with clearances of a few micrometers can be described as very poor.

Between these extremes, we distinguish between poor, average and good skills, but this classification...