Abstract: The invention relates to a removable insert for casting molds having a fastening screw for fastening the insert in the mold hollow, which screw can be moved to the fastening position by means of a screwdriver engaging an engagement region. It is provided that the engagement region of the fastening screw is oriented toward the mold hollow, and the fastening screw can be anchored in the inner wall of the mold hollow, that the insert has the cavity for the fastening screw, in which cavity the fastening screw is supported and which Cavity is accessible from the mold hollow to the screwdriver, and that the cavity receiving the fastening screw is closable in an undercut-free manner with respect to the mold hollow. The invention also relates to casting molds, equipped with such inserts, for producing workpieces.