Material bulge in rolled screw 12.9

The screw was quenched and tempered after the thread was rolled, therefore, the deformation can only be recognized by the bulges in the profile. The bulge in the tip makes 1/3 of the thread height up and is not permissible, since according to DIN EN 26157-3, bulges in the thread tip may only amount to a maximum of a quarter of the height. The edge decarburization at the thread tip also extends along the bulg.