Method for hot forging threads into an end of a steel bar

A method for hot forging and enlarging a first end of a first solid steel rod having first and opposite ends and coupling the enlarged first end of the first solid steel rod to an adjacent solid steel rod, said method including steps of:

• heating the first end of the first solid steel rod;
• surrounding the heated first end of the first solid steel rod by a die within which said heated first end is located, said die including a pair of die members, each of said die members being spaced from one another and containing a threaded recess;
• moving said pair of spaced die members together around the heated first end of said solid steel rod;
• applying an axial pushing force towards said die and against the heated first end of the first solid steel rod for compressing said heated first end and causing said heated first end to expand radially within said die to thereby create an enlarged head within the threaded recesses of said pair of die members relative to the opposite end of said first solid steel rod so that the threads of the threaded recesses of said pair of die members are imparted to the enlarged head, such that said heated first end is simultaneously threaded and enlarged within the die by the threaded recesses contained by said pair of die members;
• removing the enlarged first end of the first solid steel rod from said die and permitting the threads imparted to said first end to cool;
• and
• attaching a first threaded end of a coupler having first and opposite threaded ends to the threads of the enlarged head of the first solid steel rod, and attaching the opposite threaded end of the coupler to the adjacent solid steel rod.