Standard ring tolerances are generally defined according to ISO 286-1 and 2 standards.
For applications requiring a higher precision level : robotics, radars, etc. a better grade is considered. The tolerance values are then indicated on the bearing drawing. For bearings of large diameter with thin cross sections where radial stiffness is low, the tolerance values must be considered when bearing is fitted to its supports, these ensuring proper circularity.

GEAR
The value of the total run-out is indicated in the drawing title block. The measurement and tolerance over K teeth are also indicated on the drawing. This dimension includes the contribution of the ring to the meshing backlash.


GEOMETRY
The selected criteria are :
• For the diameters : Js 13
• For the centerings
Bores : H9
Shafts : f 9
• For the overall high: +- 1 mm

FASTENING
The bolt circle diameters are machined : to tolerance Js 10 with a minimum of +- 0.2 mm.

GENERAL TOLERANCES TABLE (According to ISO 286-2)

BEARING
. The AXIAL RUN-OUT of the supporting faces is measured using a dial gauge over one full revolution. (sketch 1)

                   
                           1                                                            2

• The RADIAL RUN-OUT of the spigots is also measured by rotation (sketch 2)

These measurements are carried out by placing the magnetic base of dial gauge on the fixed ring, while the filler is taken in contact with the element to be measured. The reading will be obtained during one rotation of the turning ring (value T.I.R.).

THE DEFLECTION UNDER MASTER LOAD is measured as follows : One of the bearing is fastened to a rigid support and a master load F is applied axially on the other ring to a point closely located to the raceway.
The deflection under load F is measured using a dial gauge whose base is attached to the other ring. The deflection under standard load of every slewing ring is measured at the factory.
This value is compared to the allowable limits, and is registered.

Deflection Under Master Load