Ferrule with relief to reduce galling

Public have an uninstall action to reduce wear and tear and bite the card sets, especially after the adoption of the ferrule appropriate improvements to make the role of the first reaction to change direction between the sleeve and the drive to make dual nut tube fitting components high partial load, due to wear and bite and big twisting force has been substantially eliminated or greatly reduced. After the ferrule tightly surrounded by the cylindrical inner wall of the pipe ends and provided continuous circumferential radial groove in the cylindrical inner wall, after the radial groove of the card sleeve ends and having a rear wall of the between. After the card holder also has a radially outer wall is substantially conical shape and has been configured to extend radially outward toward the enlarged diameter portion or flange after the ferrule. After the card sets are also included on the surface of the card after the drive sleeve forming surface and the conical wall portion of the second recess and surface-hardened, the molding surface and a drive surface engaging the drive nut.