The invention relates to a method of making what may for convenience be regarded as friction joints--that is to say, joints between the touching surfaces of two parts that are held in contact (by a force as experienced in a light interference, not one sufficient to cause forging) and that would otherwise move laterally past one another parallel to the touching plane, the method involving some minimal initial lateral movement of the two surfaces sufficient to cause some asperity deformation, leading to welding and shearing under special conditions--the phenomenon of "galling"--but not sufficient to raise the bulk temperature of either to a level where bulk welding will occur. More specifically, the invention provides a method of securing against lateral motion two bodies (12, 14) held in face-to-face (11, 12) asperity contact, thereby to make a join between the two bodies, in which method there is inserted into the interface between the two bodies a material (15) that on minimal initial lateral relative motion of the two surfaces promotes rapid but controllable "galling" (16) between the two surfaces, this galling binding the surfaces against further such motion.