The Design Factor (DF) is specified by a designer or manufacturer, and this defines the factor applied to the MBS to determine maximum load acceptable load for a component in normal use.
In general, the appropriate value for the design factor depends upon a number of considerations. Among these are:
- The extent of danger to human life and property;
- The dependability of the rigging material, the age and condition of the rigging material;
- The load conditions: static, varying, shock loads;
- The degree of knowledge of the load’s weight.
DF 5:1 or 8:1 are used in lifting operations, and 10:1 for stunt and aerial rigging when working with people on wire.