Deformed bar of steel joints screw fit, threaded and provided with deformed bar

Reinforcement (1,1) a pair of deformed bar of the present invention spiro-formed steel joints belonging to the deformed bar are connected by using male thread (1c) thereof and the barrel (2) provided in its ends. Each reinforcement (1) as a wire material made of iron by roll forming and the circumferential surface of the outer ridge (1b) shaped and other portions than the portion in the longitudinal direction of greater diameter of the enlarged diameter portion formed. The outer diameter of the enlarged diameter portion of a reinforced reinforcement comprising (1) of the ridges (1a) of the outermost diameter (D1) less. The diameter of the portion, formed by rolling the male screw portion (1c).