a method of making an improved permanently attachable coupling shell for use with coupling assemblies adapted for attachment to the end of a hose or tube used for the conveyance of fluids under pressure . the method provides a novel means of providing a plurality of solid integral three - dimensional circumferentially spaced barbs on the inner wall of the shell that controllably pierce the wall of the hose or tube to which the coupling assembly is attached and thereby increases the resistance to detachment of the assembly under pressurized and / or axially strain conditions . included in the method , is a means of reducing or preventing bulging of the uncompressed outer surface or wall portion of the hose or tube adjacent the compressed portion thereof within the attached shell member .