The jointing system has the abutting end faces of the 2 pipes (2,4) pressed together, with a friction spike (15) of a friction welding head (14) inserted radially in the pipe walls at the mating point (6) by plastic deformation. The friction spike is displaced in the peripheral direction for welding the pipes together. Pref. the peripheral displacement of the welding spike is superimposed on the radial displacement, with retraction of the welding spike by a combined radial and peripheral movement, to provide a tapered weld seam exit.
