Body and top flange: Cast iron, Seat, cone and guide: Cast bronze, Packing and diaphragm: EPDM, Yoke and diaphragm case: Ductile iron, Actuator spindle and diaphragm plate: Stainless steel grade 304, Cone stem: Stainless steel grade 316, Cover bolt: Steel, Spring: Spring steel, Adjust screw: Brass, Gasket: Non asbestos.