Comparison : Item # 305-2, Up to 500 psig Pressure 1/8 Inch (in) Thread Size Nut
Item # 305-3A, Up to 500 psig Pressure 0.628 Inch (in) - 20 Thread Size Nipple
Item # SS-24-3, Up to 500 psig Pressure Stainless Steel Nipple Assembly
Item # 284, Up to 3000 psig Pressure 0.750 Inch (in) - 14 Thread Size Female National Gas Outlet (NGO) Thread Type Brass Material Nut
Item # 283, Up to 3000 psig Pressure Brass Nipple