Therefore, in order to obtain fasteners that meet the requirements, it is usually necessary to anneal the middle sections of bolts, rivets, etc. to reduce the hardness of the middle sections, while ensuring the hardness of the heads of bolts, rivets, etc. At present, the existing process adopts ultra-high frequency induction heating equipment to instantly heat the middle section and reduce the hardness. However, this process requires a lot of control, and the heating time is slightly longer, which affects the hardness of the head, and the mass production is very unstable, which is easy to cause the rivet to fail. At the same time, the cost of ultra-high frequency equipment is high and the power consumption is large, which is not conducive to mass production and energy saving. Environmental friendly.
According to the force of the connection, it is divided into ordinary and hinged holes. According to the shape of the head: there are hexagonal head, round head, square head, countersunk head and so on. Among them, the hexagonal head is the most commonly used. Generally, countersunk heads are used where connections are required. The English name of the riding bolt is U-bolt. It is a non-standard part. The shape is U-shaped, so it is also called a U-bolt. There are threads on both ends that can be combined with nuts. It is mainly used to fix tubular objects such as water pipes or sheets such as automobile plates. Springs are called riding bolts because of the way they fix things like a person rides a horse. According to the length of the thread, it is divided into two categories: full thread and non-full thread. According to the thread type, it is divided into two types: coarse thread and fine thread. The coarse thread type is not displayed in the bolt mark. The bolts are divided into eight grades: 3.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, and 12.9 according to their performance grades. Among them, the bolts above grade 8.8 (including grade 8.8) are made of low-carbon alloy steel or medium-carbon steel and are heat-treated (quenched). + Tempering), commonly known as high-strength bolts, and below grade 8.8 (excluding 8.8) are commonly known as ordinary bolts. Ordinary bolts can be divided into three grades: A, B, and C according to the production accuracy. Grades A and B are refined bolts, and grade C is rough bolts. For connecting bolts for steel structures, unless otherwise specified, they are generally ordinary rough grade C bolts. There are differences in the processing methods of different grades. Usually the corresponding processing methods are as follows: ① The bolts of grade A and B bolts are processed by lathes, with smooth surfaces and accurate dimensions. High, rarely used; ②C-grade bolts are made of unmachined round steel, the size is not accurate enough, and its material property grade is 4.6 or 4.8. The deformation is large during shear connection, but the installation is convenient and the production cost is low. It is mostly used for tensile connection or temporary fixation during installation.
Screws are often used on objects, such as data storage, to support the objects on a bracket. Since the item will vibrate during operation or when subjected to shock, if the shock is not minimized, the item will be damaged. Therefore, some cushioning elements with cushioning properties are applied to the article. The buffer is fixed to the object by the screw. When the object vibrates, the buffer will reduce the vibration, thereby reducing the damage to the object. However, since the buffer is exposed Therefore, when the object is installed or disassembled, the object is moving relative to the bracket, and the friction between the buffer and the bracket will cause the buffer to move. It is very easy to age, thus greatly reducing its service life. SUMMARY OF THE UTILITY MODEL In view of the above, it is necessary to provide a screw combination that can protect a buffer member with buffer performance to improve its service life. A screw combination includes a screw, an elastic retaining ring and a buffer, the screw includes a nut, a threaded portion and a neck formed between the nut and the threaded portion, the retaining ring It is fixed on the neck of the screw, the buffer is sleeved on the screw, and the screw combination further includes a cover set on the screw, and the cover includes a top and a forming part. In the shielding part of the top, the top is located between the nut and the retaining ring, and is blocked by the nut and the retaining ring so as not to be separated from the screw, and the shielding part covers the The retaining ring and the buffer element are slightly exposed from the shielding part. Compared with the prior art, the screw assembly of Guangdong Yueluo Hardware Industry Co., Ltd. protects the buffer by covering the buffer by the shutter, thereby increasing its service life.
Ordinary open rivet is a kind of product in rivet. It is riveted to the workpiece by expanding the rivet body after the big end of the mandrel is pulled. After the traditional rivet is riveted, the operator will cut the mandrel short, the mandrel does not work, and the workpiece is riveted by the material strength of the rivet body itself. After the mandrel is pulled, the middle of the rivet body becomes a cavity, and the mandrel shears The distance of the segments is relatively random. The random shearing determines the length of the cavity of the riveting body, and the length of the cavity determines the tensile and shear strength of the riveting body. The volume of the cavity is large, the tensile and shear strength is low, and the cavity is small. , the tensile and shear strength is slightly improved, so the breaking point of the rivet can completely affect the use effect of the rivet.
The common types of wood screws are iron and copper, and the types are divided into round head type and other samples of wood screws according to different nail heads. There are two types of slotted screws and cross recessed screws. Generally, the round head screws are made of mild steel and are blue, and the flat head screws are polished. The oval head screws are usually plated with cadmium and chrome, and are often used to install hinges, hooks and other hardware accessories. Specifications are determined by rod diameter, length and nail head type. [1]
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: standard specifications and models of spring washers, claw nuts, 304 hexagon socket bolts, PCB support columns and other products, we can provide you with suitable fastening products piece solution.