Connections for Fluid Power and High Pressure Use - Ports, Stud Ends, and Plugs with ISO 261 Threads and O-Ring Sealing - Part 3: Port Plug Requirements, Dimensions, Design, and Test Methods (Stabilized: Jan 2017)
This part of SAE J2337 specifies dimensions, design, and performance requirements for eight plugs using a conical seal to insure leak proof performance with a design factor of 4 to 1.