The DIN 933 and ISO 4017 are international standards that define the specifications for hexagon head bolts. These standards cover the dimensional and mechanical properties of hexagon head bolts with threads from M1.6 to M64. They provide precise guidelines for the head height, width across flats, and thread lengths, ensuring interchangeability and compatibility between different manufacturers and countries. Additionally, the standards outline the materials and surface finishes that can be used for these bolts, guaranteeing their durability and corrosion resistance. DIN 933 and ISO 4017 play a crucial role in promoting consistency and quality in the production and use of hexagon head bolts across the globe.