Ball joint, and stabilizer link using same

A ball joint comprising:

• a ball stud fastened at one end to a structure body, and including a ball part at an opposite end;
• a housing turnably supporting the ball part of the ball stud;
• and
• a ball seat provided existing between the housing and the ball part, and including a holding part for the ball part, wherein:
• the ball seat is formed by injection molding where a thermoplastic first resin is injected into a first mold, and is provided in the housing by insert injection molding where a thermoplastic second resin from which to mold the housing is injected into a second mold with the ball seat inserted in the second mold while the ball part is being held in the holding part of the ball seat, and
• an inner diameter dimension of the holding part formed in the ball seat by the injection molding is set at a dimension greater enough to accommodate an amount of molding shrinkage of the first resin after the injection molding, and an amount of molding shrinkage of the second resin after the insert injection molding, the amount of molding shrinkage depending on an injection temperature and an injection pressure of the second resin during the insert injection molding.