This part of SAE J2244 specifices dimensions, performance requirements, and test procedures for metric external hex O-rings port plugs. Port plugs in accordance with this part of SAE J2244 may be used at working pressures up to 63 MPa. The permissible working pressure depends upon materials, design, working conditions, applications, etc. For threaded ports and stud ends for use in new designs in hydraulic fluid power applications, only SAE J2244 shall be used. Threaded ports and stud ends in accordance with ISO 1179, ISO 9974, and SAE J1926 (ISO 11926) shall not be used in new designs in hydrualic fluid power applications. Conformance to the dimensional information in this document does not guarantee rated performance. Each manufacturer shall perform testing according to the specification contained in this document to ensure that components made to this document comply with the performance ratings.