Abstract: A ball joint is disclosed having a socket, a ball received by the socket and a stud extending outwardly from the ball. A ball seat member is received in the socket and has a soft portion with an inner spherical surface which covers the portion of the ball at the side opposite to the stud. The soft portion is axially compressed by a cap closing an opening in the socket opposite to the stud, while expanding radially outward to be penetrated by linear projections formed in a hard portion of the ball seat member. Further, a gap remains between the soft portion after it has expanded radially outwardly and the inner cylindrical surface of the hard portion of the ball seat member so that the soft portion of the ball seat member contacts the hard portion of the ball seat member only at the linear projections.