Sec. 23.693 - Joints.
Control system joints (in push-pull
systems) that are subject to angular motion, except those in ball and
roller bearing systems, must have a special factor of safety of not less
than 3.33 with respect to the ultimate bearing strength of the softest
material used as a bearing. This factor may be reduced to 2.0 for joints
in cable control systems. For ball or roller bearings, the approved
ratings may not be exceeded.