Ball stud of ball joint for vehicle and method of manufacturing the same

A method of manufacturing a ball stud of a ball joint for a vehicle, comprising:

• forming a ball stud body made of metal, the ball stud body comprising:
• a flange;
• a connection part provided on the flange, the connection part having a cylindrical shape;
• and a threaded part provided on the connection part such that the threaded part is coaxial with the connection part, with a thread formed on the threaded part, the threaded part having an outer diameter greater than a diameter of the connection part;
• forming a funnel-shaped auxiliary plate made of metal and having a coupling hole on a central portion of a lower end thereof, the coupling hole having a diameter greater than an outer diameter of the threaded part, the funnel-shaped auxiliary plate having a support area greater than a support area of the flange;
• and
• inserting the threaded part of the ball stud body into the coupling hole of the funnel-shaped auxiliary plate, and pushing the funnel-shaped auxiliary plate towards the flange of the ball stud body until the central portion of the lower end of the funnel-shaped auxiliary plate comes into contact with the flange, and then pressing the funnel-shaped auxiliary plate supported on the flange into a planar shape, whereby the coupling hole is reduced by the pressing to have a diameter less than the outer diameter of the threaded part.