Designed to be used with the heavy duty fasteners referenced on the table. Receptacle is mounted with three low head cap screws (M3x0.5 - 6mm long, included). The body is made from SAE-1045 steel with an electroless nickel plate finish. The balls ae made from SUS440C stainless steel. The collar is made from SKS3 steel with an electroless nickel plate finish. The retaining ring is made from 304 stainless steel.