There are countless standard parts on the market, if you want to buy standard screws, there will be standard screws. Let's talk about screw standard parts first. Screws are usually called in the industry. Screws usually include screws and bolts. There are many standards in the general market: DIN912 (GB70-85) hexagon socket screws. Its minimum size can reach M2 (the screw diameter and thread length are not limited). For example: M2.5 M3 M4 M5 M6 M8 M10 M12 M14, etc. (the length is not limited). What is the specification of the standard screw? It consists of the thread (the distance between the thread and the thread), the diameter of the threaded rod and the length of the threaded rod of the screw (excluding the head). Let us take the above standard part data as an example. For example: the minimum specification M2, its professional standard name is: M2-0.4X5 (0.4 is the pitch, M2 is the length of the screw, and 5 is the diameter of the screw). The materials of general standard pa...