This standard has been prepared by the German engineering community and has provided a complete list for all types of bolts and nuts in terms of shape, class, grade, size, length and pitch. The use of DIN standard in bolts and nuts is very common not only in Iran but all over the world due to the high accuracy and considering the details in the selection of bolts and nuts. It is worth mentioning that Germany, the founder of this standard is the heart of Europe in producing the fittings and fasteners, and many countries directly purchase their required bolts and nuts for military and heavy industries from this country.

This standard, which was explained by the American Society of Engineers, is older than other bolt and nut standard systems and mostly explains the material and raw materials of production, and it is actually a technical standard that includes many items of industrial products. Unlike the DIN standard, which deals a lot with the dimensions, sizes and shapes, the ASTM standard of the American system deals more with the production temperature, the production process, and the material used in the construction of bolts and nuts.