I think before we go much further the OP should maybe post a picture of which connector they are talking about...
a google for fastlink shows these:
but based on the above posts...
The little round brass critters
the set screw really jammed into the wire,
The Great Planes version of those little critters are called "screw-lock pushrod connectors" and the main body is brass and square in cross section
so it seems that there are several different connectors being discussed...
a little clarification would be wise....