The factor of safety is used in designing a machine component. Prior to selecting the correct factor of safety certain points must be taken into consideration such as:

☛ > The properties of the material used for the machine and the changes in its intrinsic properties over the time period of service.

☛ > The accuracy and authenticity of test results to the actual machine parts.

☛ > The applied load reliability.

☛ > The limit of stresses (localized).

☛ > The loss of property and life in case of failures.

☛ > The limit of initial stresses at the time period of manufacture.

☛ > The extent to which the assumptions can be simplified.

The factor of safety also depends on numerous other considerations such as the material, the method of manufacturing , the various types of stress, the part shapes etc.