The national standard for the size of the screws in the round head three-combination screw is GB818. The main technical requirements of various types are: iron and stainless steel for material requirements, low, medium and high carbon steel for iron, and stainless steel combination screws The materials are stainless steel 201, stainless steel 304 and stainless steel 316. The thread tolerance is 6G, and the mechanical properties of the iron combination screws are 4.8 and 8.8. The 4.8-level combination screws are ordinary steel, and the maximum allowable hardness is 255HV. The 8.8-level combination screws are generally made of wire rod 10B21. , and then undergo hardening treatment, and then dehydrogenation after hardening treatment. Hydrogen removal is to prevent hydrogen embrittlement of the spring washer in the combination screw. Prevent the spring pad from breaking. The tolerance class of the combination screws is A. The cross groove is H-shaped. The surface treatment of the combination screw has environmental protection and non-environmental protection. Such as, environmental protection blue zinc, environmental protection color zinc, black zinc, color zinc, white nickel and so on. The technical requirement of the combination screw for the spring washer is that the washer should be able to rotate automatically without falling off.
The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to overcome the above shortcomings and provide a limit screw. The technical scheme of Guangdong Yueluo Hardware Industry Co., Ltd. is realized in the following way. Its structure is composed of screws, hexagonal copper posts and limit necks. The left end of the limit neck is open, the hexagonal copper column is communicated with the inside of the limit neck, and the inside is provided with screw threads. The design length of the screw thread in the hexagonal copper column is 1/3-2/3 of its own length. The advantages of Guangdong Yueluo Hardware Industry Co., Ltd. are (7), which can effectively prevent the problem of poor memory contact caused by the increase of the deformation of the motherboard due to the warping and deformation of the motherboard during installation and fixation, and can effectively control the amount of deformation effect.
Nuts are parts that tightly connect mechanical equipment. Through the inner threads, nuts and bolts of the same specification can be connected together. For example, M4-P0.7 nuts can only be connected with M4-P0.7 series bolts (in the nut). Among them, M4 means the inner diameter of the nut is about 4mm, and 0.7 means that the distance between the two threads is 0.7mm); the same is true for American products, for example, a 1/4-20 nut can only be matched with a 1/4-20 screw ( A 1/4 finger nut has an inner diameter of about 0.25 inches, and 20 fingers have 20 teeth in each inch).
It can be seen from the figure that no matter how the screw core swings, it will not fall off from the screw sleeve. This is because part of the bead 5 is stuck in the hole 6 of the screw sleeve 1 and the other part is stuck in the screw core 2. In the groove 8, it plays the role of positioning. If the screw sleeve rotates clockwise, the beads 5 can only slide in the groove 8 of the screw core 2 under the driving of the screw sleeve 1 and cannot drive the screw core 2 to rotate. If the screw sleeve 8 rotates in the opposite direction, the bead 5 will be stuck on the stop 7 of the screw core 2 so as to drive the screw core 2 to rotate.
Stamping die is a special process equipment for processing materials into parts in cold stamping processing, called cold stamping die. Stamping is to use the die installed on the press to apply pressure to the material at room temperature to make it produce Separation or plastic deformation to obtain the required parts of a pressure processing method, the technology generally used is to make corresponding holes and punches on the template, this method cannot meet the requirements for small batches and short delivery time products , the relative cost is relatively high, so a rivet die structure is required to improve the above problems.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: anti-corrosion grade 8.8 screws, lifting ring screws and nuts, H62 copper DIN933 screws, wood lock nuts and other products, we can provide you with suitable fastening products piece solution.