The 2H hex nut is used in conjunction with screws, bolts, and screws to connect and tighten parts. Among them, type 1 six-purpose nuts are the most widely used. Grade C nuts are used for machines, equipment or structures with rough surfaces and low precision requirements; Grade A and B nuts are used for smoother surfaces and higher precision requirements. On the machine, equipment or structure. The thickness M of the type 2 hex nut is relatively thick, and it is mostly used in occasions that often require assembly and disassembly. The thickness M of the hexagonal thin nut is thin, and it is mostly used in occasions where the surface space of the connected parts is restricted.

As the height of the nut increases, the guaranteed stress index can be achieved at a lower quenching and tempering hardness, so the toughness of the nut is increased. Classified by tooth distance: standard teeth, regular teeth, fine teeth, very fine teeth and reverse teeth. Classified by material: stainless steel hexagon nuts and carbon steel hexagon nuts, copper hexagon nuts, iron hexagon nuts. Classified by thickness: hexagonal thick nuts and hexagonal thin nuts. Classified by method of use: hot-melt copper nuts, hot-pressed copper nuts, embedded copper nuts and ultrasonic copper nuts.

There are generally two types of 2H hex nut, one is iron, which is carbon steel. One is stainless steel, and of course there are copper and aluminum nuts, but these are less used. Copper is still somewhat useful, and nuts like aluminum are rarely used.