Machining method and die assembly of T-bolt

The invention discloses a machining method and a die assembly of a T-bolt and belongs to the field of machining of T-bolts. The machining method comprises the following steps that 1) metal is subjected to closed extrusion and upsetting in a movable die cavity, pre-upsetting of the shape of the head portion of a product is completed, the pre-upsetting shape of the heat portion of the product is similar to a trigonal section, reducing is performed on materials while the head portion is subjected to upsetting; 2) the head portion of the product is subjected to preliminary upsetting, a cuboid withthe head top provided with a circular arc is formed, meanwhile, a rod portion is subjected to extrusion reducing, and chamfering forming is performed at the rod end; and 3) the final upsetting is performed on the head portion by means of an upper semicircular die body and a lower semicircular die body, a head cylindrical shape is formed, and meanwhile, size forming of the rod portion and a threaded portion is completed.