Abstract: A pivot joint including a mounting frame, a pivot bolt inserted through a hole on the mounting frame, and a lock nut screwed up with the pivot bolt to hold the mounting frame and the pivot bolt together, permitting the pivot bolt to be turned about its longitudinal center axis, wherein the pivot bolt has a collar stopped against the mounting frame at one side opposite to the lock nut; two washers are mounted around the pivot bolt and retained between the mounting frame and the lock nut; a plurality of corrugated plate springs are mounted around the pivot bolt and retained between the washers.