• 1/2" MNPT G style plugs are made of case hardened steel and are plated to resist rust. Milton G style couplers and plugs offer 1/2" basic flow size and a maximum of 300 PSI. With air flow of up to 99 SCFM, G style couplers are perfect for applications that require over 60 SCFM. • 1/2" male national pipe thread • Maximum inlet pressure of 300 pounds per square inch • Air flow of 99 standard cubic feet per minute • Maximum temperature of 250 degrees Fahrenheit • 1/2" male national pipe thread • Maximum inlet pressure of 300 pounds per square inch • Air flow of 99 standard cubic feet per minute • Maximum temperature of 250 degrees Fahrenheit