1968 McDonnell Aircraft developed the technology to 360 degree radial swage compression tube coupling for F- 4 Fighter jets.They licensed DMC of California to manufacture the fitting.In 1978 DMC patent system called PYPLOK DMC entered into Petrochemical and other industrial markets. There was an ownership change in 2004.DMC’s new management decided to focus on their core aerospace and power business so they offered the PYPLOK line to Tube-Mac.In January 2007 the sale was completed. Tube-Mac took over the marketing, design and manufacture of The PYPLOK