Threaded Rods And Eye Bolts Are Evenly Stressed Individuals1 week ago - Multimedia - Chinatown - 17 views
Hexagon Flange Bolt generally adopts cold working, so that the thread blank in a certain diameter range passes through the rolling (rolling) wire plate (die), and the thread is formed by the pressure of the wire plate (rolling die). The plastic flow line of the threaded part can be obtained without being cut, the strength is increased, the precision is high, and the quality is uniform, so it is widely used. In order to produce the outer diameter of the thread of the final product, the required thread blank diameter is different, because it is limited by factors such as thread accuracy, whether the material is coated or not. Rolling (twisting) pressing thread refers to a processing method that uses plastic deformation to form thread teeth. It uses a rolling (thread rolling plate) mold with the same pitch and tooth shape as the thread being processed. While squeezing the cylindrical screw blank, the screw blank is rotated, and finally the tooth shape on the rolling mold is transferred to On the screw blank, the thread is formed. Rolling (rubbing) pressing thread processing has the common point that the number of rolling revolutions does not need to be too much, if too much, the efficiency is low, and the thread tooth surface is prone to separation phenomenon or buckling phenomenon. Conversely, if the number of revolutions is too small, the thread diameter is easily out of round, and the initial pressure during rolling is abnormally increased, resulting in a shortened die life. Common defects of rolling thread: cracks or scratches on the surface of the thread part; buckling; the roundness of the thread part. If these defects occur in large quantities, they will be discovered during the processing stage. If the number of occurrences is small, the production process will circulate to the user without noticing these defects, causing trouble. Therefore, it is necessary to summarize the key issues of processing conditions and control these key factors in the production process. Common bolts are generally 4.4, 4.8, 5.6 and 8.8. High-strength bolts are generally grade 8.8 and grade 10.9, of which grade 10.9 is predominant. Level 8.8 is the same as 8.8S. The mechanical properties and calculation methods of ordinary bolts and high-strength bolts are different. High-strength bolts are first subjected to a pre-tension force P inside, and then generate frictional resistance on the contact surface between the connected parts to bear the external load, while ordinary bolts directly bear the external load. Ordinary bolt connection has no requirements for the axial force of bolt tightening, so the tightening construction of bolts is subject to the operator's feel and the shape control of the connection joint. Generally speaking, an operator uses an ordinary wrench to tighten the nut with his own strength. To ensure that the contact surfaces to be connected can be closely adhered, without obvious gaps. Although this type of fastening construction has great differences, it can meet the connection requirements. In order to make the bolts in the joints evenly stressed, the tightening sequence of Threaded Rods And Eye Bolts should start from the middle and proceed symmetrically to both sides.