Body, Cap, Disc Retaining nut (3 inch only), Hinge, Hinge pin plug: Bronze; Disc Holder, Disc Retaining nut (1/2 - 2 1/2 inch), Washer, Hinge nut, Hinge Pin (2 1/2 & 3 inch): Brass; Disc: Nitrile rubber; Hinge Pin: Stainless steel (1/2 - 2 inch); ID Plate: Aluminium; Drive Pin: Steel-electro brassed.