This machine screw and lock nut set is the correct length and diameter to replace a worn out gooseneck bolt. You may find that the gooseneck is loose and repeated tightening of the nut is not working - this maybe because the lock nut is worn out or that the gooseneck plug in the boom has worn out.

1 x M6 x 25mm Hex Head Machine Screw A4

1 x M6 Nyloc Nut A4