This article describes a method for hot-forging T-clamps using a simple form. Another perfectly functional cold-bending method is described on the Making T-clamps page.
T-clamp forging form Edit
The forging form can be made from flat steel bar that is 5mm thick or thicker. A slot is cut to its side for a perpendicular piece of the same steel:
The pieces are welded together from the bottom side:
The part of the flat bar below the crosspiece is used to attach the form to an anvil or a vise.
Forging T-clamps Edit
First cut a piece of steel strip that is slightly longer than necessary. Then cold-bend it to a shallow V-form. It is also beneficial to bend its ends into the opposite direction:
Heat the to-be T-clamp in a forge. Once hot, forge it against the form with two hammers of (roughly) equal weight simultaneous and in sync from both sides. Alternatively you can just squeeze the sides against the form using pliers. Carefully forge the steel strip agains the top part and bottom parts of the form, so that the characteristic T-shape emerges:
The forged T-clamps will probably look a bit funky at first, because of the extra steel at the ends:
Cut away excess steel and do any minor bending or straightening while the clamps are cold.