DIN 6921 is a standard that specifies the requirements for hexagon flange bolts with a non-serrated flange and a metric thread. These bolts are commonly used in various industries and applications where a secure and reliable fastening solution is required. The standard outlines the dimensions, materials, and mechanical properties of the bolts, ensuring that they meet the necessary quality and performance standards. DIN 6921 provides a clear and consistent guideline for manufacturers and users, facilitating the interchangeability and compatibility of these bolts across different systems and equipment.