Fastener element for a fastening system, fastening tool, disengagement and testing of a fastener element, method for providing a fastening system with a closure seal and/or a torque indicator

A method for providing a fastening system with a fastening seal or a torque indication, comprising the steps:

• providing a fastener element of the fastening system-with a tool engagement surface that is engageable by a tool for at least partial form locking contact with the tool for fastening or disengaging the fastening system;
• providing the tool engagement surface with at least one weak spot which facilitates a deformation of the weak spot or at least a deformation or weakening of a portion adjacent to the weak spot;
• imparting a particular torque from the tool to the tool engagement surface;
• and
• indicating an unauthorized use or an authorized use with a sufficiently large torque,
• wherein the tool engagement surface is configured as a straight slot, or cross slot, or external polygon, or internal polygon, or external involute, or internal involute, or Ribe, or Torx®, or Tri-Wing™, or Torq-Set, or Torx®-Tamper or Pentalob,
• wherein the tool is a straight slot, or cross slot, or external polygon, or internal polygon, or external involute, or internal involute, or Ribe, or Torx®, or Tri-Wing, or Torq-Set, or Torx®-Tamper or Pentalob tool.