seen that the front ferrule 36 includes an axially rearwardly extending cylindrical flange portion 66 that defines a cylindrical bore 68 leading to the force receiving inclined surface 46 this flange portion 66 preferably extends along a significant length of the rear ferrule or the cylindrical body portion 54 to radially constrain the rear ferrule the flange portion 66 may extend less than half along the cylindrical body portion however other lengths of the flange 66 such as greater than half the length of the cylindrical body portion or about one fourth of the length of the rear ferrule 54 or other varying lengths may still be utilized the flange portion 66 preferably has a thickness sufficient to prevent buckling of the central body portion 54 accordingly the flange portion 66 is preferably thicker than the body portion 54 to prevent outward buckling of the central body portion and in one embodiment the central body 54 is less than about two thirds of the thickness of the flange portion 66 as can be seen in fig4 the outer diameter of the flange portion of the front ferrule 36 is radially outward of the rear ferrule thus in the illustrated embodiment the front ferrule 36 has an outer diameter greater than the rear ferrule 34 as best shown in fig4 the flange portion 66 of the front ferrule 36 is radially spaced from the central body portion 54 of the rear ferrule 38 a ferrule.