Customized Iron Cross Countersunk Head Screws Galvanized Cross Flat Head Screws Countersunk Head Screws Flat Machine Screws GB819

Generally, the most commonly used material on the market is iron. The iron one is known as carbon steel. It is punched out or turned. After being manufactured, it is in its natural color. In order to prevent rusting, it is necessary to Electroplated. The stainless steel rivet nuts do not need electroplating. In the case of iron, the color of electroplating is generally determined by the customer, and the color of the electroplating depends on what color the customer needs. There are also some requirements for salt spray time. Some electroplating colors have a higher salt spray time, and some electroplating, less rust in a few hours. Another point is to see whether the customer needs to export the product. Generally, the export needs to be environmentally friendly, and some domestic ones also need it, but most of them are not needed.

Nuts are used as fasteners, and most of them need to be used in conjunction with gaskets in the process of use to adjust the deficiencies of the material itself and strengthen the degree of tightening, while metal materials are used as raw materials for gaskets. The cost is also relatively high, and in the process of use, the end face of the metal gasket and the nut will also be affected by the process, resulting in the defect that the fastening effect is not firm and easy to loosen.

The bolt thread is generally cold worked, so that the thread blank within a certain diameter range passes through the rubbing (rolling) wire plate (die), and the thread is formed by the pressure of the wire plate (rolling die). The plastic streamline of the threaded part is not cut off, the strength is increased, the precision is high, and the quality is uniform, so it is widely used. In order to make 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 and whether the material is coated or not. Rolling (rubbing) thread is a processing method that uses plastic deformation to form thread teeth. It uses a rolling (screwing plate) die with the same pitch and tooth shape as the thread to be processed, while extruding the cylindrical screw blank, while rotating the screw blank, and finally transferring the tooth shape on the rolling die to the On the screw blank, the thread is formed. The common point of rolling (rubbing) thread processing is that the number of rolling revolutions does not need to be too much. If it is too much, the efficiency will be low, and the surface of the thread teeth will easily cause separation or random buckle. On the contrary, if the number of revolutions is too small, the diameter of the thread is easy to be out of round, and the pressure at the initial stage of rolling increases abnormally, resulting in a shortening of the life of the die. Common defects of rolled threads: cracks or scratches on the surface of the thread part; random buckles; out of roundness of the thread part. If these defects occur in large numbers, they will be discovered during the processing stage. If the number of occurrences is small, the production process does not notice these defects and then circulates to users, causing trouble. Therefore, the key issues of processing conditions should be summarized, and these key factors should be controlled in the production process.

In terms of screw standard specification broadcast, there are two versions of the national standard, one is GB70-76, the 76 version, and the other is GB70-8585 version. Our company is now implementing the DIN912 standard, so it should be paid attention to in actual business operations. Difference: GB70-85 and DIN912 completely overlap, so there is no difference in the use of the new standard, mainly because there is a difference between GB70-76 and DIN912: M8 series hexagon products, GB70-76 round head diameter It is 12.5MM, which is smaller than 13.27MM of DIN912. For M10 series inner hexagon products, the round head diameter of GB70-76 is 15MM, which is smaller than 16.27 of DIN912. The inner hexagon of M12 series, the round head of GB70-76 The diameter is 18MM, which is smaller than the opposite side of DIN912, which is 18.27. In addition, the round head diameter of the inner hexagon GB70-76 of M16 and M20 series is 0.33MM smaller than that of DIN912, which are 24MM and 30MM respectively. DIN912 is 24.33MM and 30.33MM respectively. In addition, the width of the inner hexagon between the old standard and the German standard is different due to different standards. The inner side of GB70-76 is smaller, and it should be paid attention to in business operations. In addition, there are also some differences in the carriage screws that may be used at ordinary times. I will also make an explanation here. In the national standard, there are two standards for carriage screws, namely GB12 (small semicircular head square neck screw) and GB14 (large semicircular head square neck screw) Neck screws), and the German standard DIN603 is usually more commonly used in the market. Now to distinguish these three: for the round head and neck, when comparing the same specifications: GB12. Usually when the carriage screw is used, the head and neck are often required to be large and thick, so the standard of DIN603 carriage screw fully meets the requirements.

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