The pivot pin mounts to the side of the dump body. The pin is 3-1/2" long and 1-3/4" thick, with a notch along the pin to fixedly seat the spiral torsion springs. The mounting plate is 8" x 3-5/8". The pin is welded to the mounting plate. All material are made of steel. The mounting plate has two 5/8" holes, spaced 5-1/2" apart.