DIN 557 specifies the dimensions and technical requirements of square nuts. These nuts are especially designed to be used with bolts and studs in structural steel engineering and construction. The standard covers the physical properties and material specifications of square nuts, ensuring that they meet the necessary strength and durability for their intended applications. Additionally, DIN 557 provides details on the thread sizes and pitch, as well as the tolerances for the nuts. This standard plays a crucial role in ensuring the safety and reliability of structural steel assemblies by providing clear guidelines for the manufacturing and use of square nuts.