be spaced a slight distance from the outer periphery of tube 15 so that tube 15 may be freelyinserted into counterbore 35 similarly first and second bite edges 44 45are dimensioned so that their tips are free of tube 15 upon further threaded engagement of nut 12 with respect to body member 14 nut 12 will be moved to the right as viewed in fig1 and 2 to the final position depicted in fig2 during this movement nut conical cam surface 28 engages sleeve conical surface 41 to collapse the rearward end of sleeve 11 in a substantially solely radial direction forcing cutting edges 44 45to penetrate into the outer periphery of tube 15 to the position depicted in figure 2 during the collapsing movement of the outer end of sleeve 11 dogleg 58 will be similarly collapsed to the position depicted in fig2 where intersection surface 62 will be in tight engagement with the outer periphery of tube 15 and somewhat slightly embedded therein the degree ofembedment of intersection surface 62 into the surface of tube 15 will depend upon the relative hardness of sleeve 11 and tube 15 the degree of curvature of intersection surface 62 the shape and configuration of the forward conical section 60 and rear conical section 59 of sleeve 11 and further considerations however in any event rear wall 52 of groove 50 will be deformed a few degrees toward a more nearly vertical position as depicted in fig2 in the final assembled condition of fig2 rear wall 52 completely closes the rearward end of groove 50 preventing extrusion ofseal 55 rearwardly of groove.