A saddle-joint jig (2) for reproducing the line of contact of a first tube (20) in relation to a second tube (22) so that the first tube (20), when cut along that line, may be joined in edge-to-edge abutment to the second tube (22) in that same relation; which jig (2) comprises at least three generally parallel pins (8) each of which is slidingly held to allow each pin (8) to slide longitudinally when a force is applied thereto; the pins (8) being held in a band that, in use, is capable of circumferentially enclosing the first tube (20).
