A device for the connection and the locking of two parts (30a, 30b), including a female part (10) comprising two bars (12), a male part (21) cooperating with this female part (10), and a hinged flap (17). Each bar (12) contains two balls (2a, 2b) and at least one movable inner stop (5) arranged between the balls (2a, 2b). The axial length of the movable stop (5) plus the diameters of the two balls (2a, 2b) is greater than the distance between the two lateral faces of the branch (11a, 11b) in which the ball bar (12) is situated. Also provided is a method for the connection and the locking of two parts, a ball bar, and a method for producing the latter and to the uses thereof.