Production of 10.9 grade medium thread fine thread hex head screws and bolts 3/4 5/8

Due to the high demand for electronic products and the reduction of assembly line workers, in order to cope with the problem of labor shortage, manufacturing factories need to use automatic screw locking equipment to replace manual labor. In the existing automatic locking and paying equipment, most of them use a screw arranging machine to arrange the screws, and an electric screwdriver (electric batch) takes the screws back and forth, or the special equipment blows the screws into the electric batch to send the screws to the electric batch, and back and forth. The method of taking is too time-consuming, and the method of blowing air is not suitable for screws with small aspect ratios.

When the countersunk head screws and hexagon socket head bolts are produced by the cold heading process, the original structure of the steel will directly affect the forming ability of the cold heading process. In the process of cold heading, the plastic deformation of the local area can reach 60%-80%, so the steel must have good plasticity. When the chemical composition of the steel is constant, the metallographic structure is the key factor to determine the plasticity. It is generally believed that the coarse flaky pearlite is not conducive to cold heading forming, while the fine spherical pearlite can significantly improve the plastic deformation ability of the steel. For medium carbon steel and medium carbon alloy steel with a large amount of high-strength bolts, spheroidizing (softening) annealing is performed before cold heading, so as to obtain uniform and fine spheroidized pearlite to better meet the actual production needs. For the softening annealing of medium carbon steel wire rods, the heating temperature should be kept above and below the critical point of the steel, and the heating temperature should not be too high, otherwise tertiary cementite will precipitate along the grain boundary, resulting in cold heading cracking. The wire rod of medium carbon alloy steel is annealed by isothermal spheroidization. After heating at AC1+ (20-30%), the furnace is cooled to slightly lower than Ar1, the temperature is about 700 degrees Celsius for an isothermal period, and then the furnace is cooled to about 500 degrees Celsius and air-cooled. The metallographic structure of the steel changes from coarse to fine, from flake to spherical, and the cracking rate of cold heading will be greatly reduced. The general area of softening annealing temperature for 35\45\ML35\SWRCH35K steel is 715-735 degrees Celsius; while the general heating temperature for spheroidizing annealing of SCM435\40Cr\SCR435 steel is 740-770 degrees Celsius, and the isothermal temperature is 680-700 degrees Celsius.

A rivet is a nail-shaped object used to connect two parts (or members) with a through hole and a cap on one end. In riveting, the riveted parts are connected by their own deformation or interference. There are many types of rivets, and they are informal.

Guangdong Yueluo Hardware Industry Co., Ltd. provides a screw positioning pin, which is composed of a main body part and an insert part. The main body part is a circular boss structure, and the bottom of the circular boss structure is provided with a rectangular groove. The inserting part is fixed on the middle part of the upper surface of the main body part, the lower part of the inserting part and the contact section of the main body part are in a circular truncated structure, the upper part of the inserting part is a cylindrical structure, and the outer surface of the cylindrical structure is provided with threads; the screw positioning pin , The structure is simple and the design is ingenious. The special structural design of the main part and the insert part can be positioned between the punch and the die in the first processing process, effectively reducing the gap formed during the processing between the punch and the die. Firmly fixed, suitable for the needs of large-scale industrial production.

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