DIN 931 and ISO 4014 are two different standards for fasteners. DIN 931 is a German standard, while ISO 4014 is an international standard. These standards specify the dimensions, materials, and other requirements for hexagon head bolts with partial threads. The main difference between the two standards lies in their origin and the specific requirements they outline. While DIN 931 is widely used in Germany and some other European countries, ISO 4014 is recognized and used globally. Both standards ensure the quality and compatibility of these bolts in various applications, providing a standardized solution for fastening needs.