The DIN 7991/ISO 10642 standard specifies the characteristics of countersunk flat head screws with hexagon socket head, which allows for a flush finish when installed. These screws are commonly used in applications where a smooth, low-profile fastening solution is required, such as in machinery, automotive, and aerospace industries. The standard outlines the dimensions, materials, and tolerances for these screws, ensuring interchangeability and compatibility across different manufacturers. Additionally, it provides guidelines for the use of these screws in various materials, such as steel, stainless steel, and non-ferrous metals, further increasing their versatility. Overall, DIN 7991/ISO 10642 sets the benchmark for high-quality, reliable countersunk flat head screws that are essential components in a wide range of engineering and construction projects.