Non-standard screws refer to non-specific standard screw products. For example, clothes and shoes in daily life are produced according to a set of standard sizes. Such as M code. If the size you want is not the standard of this kind of regulation, it is called non-standard. Another example is that there are a large number of standard products in the industry, such as screws. It only has two sizes of M6 and M7 . If you have to make a M6.5 , it is a non-standard screw.
There are many varieties of non-standard screws, such as hexagon socket screws, 7- shaped bolts and so on. At present, there is no standard classification. They are generally independently developed by companies based on market needs and their own brand development to extend the vitality of products.
