methods of forming joints between bars of materials such as mild steel are disclosed . in one method , the bars are arranged to lie in generally parallel planes but with their axes at an angle to one another , and a plastically - deformable tubular stub of round or square cross - section is disposed between the bars with its axis substantially intersecting the axes of the bars , which are then pressed together to deform the stub partially around the two bars . in a second method , a bar is arranged in a t - formation with a hollow member , two opposed regions at the end of the tubular member are deformed inwardly and back along the member axis , and the bar is then pressed into the groove so - formed at the end of the member , to deform the end portion partially around the bar . heat may be used , in the former case on the stub and in the latter case on the tubular member , so that after completion of the joint the heated stub or tubular member will cool and contract , firmly to grip the or each bar .