The three parts of SAE J1453 cover material, dimensional, and performance requirements of steel O-ring face seal (ORFS) connectors for tubing and the O-ring face seal interface and nut portion of hose stem assemblies for nominal tube diameters of 6 mm through 38 mm and for nominal hose diameters 6.3 mm through 38 mm. SAE J1453-2 covers the requirements for “metric based” O-ring face seal connectors to metric stud ends along with the associated adapters, bulkhead and union connectors. Metric hex wrenching flats are used throughout this standard.