Production of t-shaped gaskets, transistor gaskets, nylon bushings, insulating particles, t-shaped gaskets

Nuts and bolts are one of the most widely used fasteners in modern mechanical structures. At present, the common metric bolts and nuts are generally trapezoidal in cross-section. The connection between the bolt and the nut is prone to loosening under severe vibration, or even falls off by itself, and the tightening force of the bolt and nut thread is mainly concentrated in the bolt thread and Between the teeth of the first few threads where the threads of the nut are in contact, resulting in loosening of the fastener and sliding pressure of the threads

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.

The national standard name of the cross recessed small pan head three combination screw is the cross recessed small pan head screw, the spring washer and the flat washer assembly. The national label is GB/T9074.8-1988. This 1988 refers to the year, that is, this standard is the standard issued by the country in 1988. The specifications of the cross recessed small pan head three combination screws, the company's minimum is M2.5, the shortest is 5mm, the largest is M10, and the longest is 90mm.

At the beginning of the quality inspection process broadcast, we ordered the cross recessed screw and screw wire material into our production screw industry. For manufacturers in the screw industry, we must first detect the wire diameter of the screw wire and the material of the screw. Generally, the wire diameter of the screw is measured by a caliper and a measuring wire. Diameter size, whether it is the same as the size ordered by yourself. After testing these, it is the testing in the production process, starting from the head of the screw, to determine the size of the head, the opposite side of the head, the diagonal angle, the depth of the cross groove, the tolerance range of the screw, and so on. These are checked with calipers. In the inspection of all aspects when rolling teeth, the main thing is whether the thread can pass the pass and stop gauge, and whether the screw thread can pass the gauge and stop. Next is the electroplating measurement problem. After electroplating, whether it meets the requirements of environmental protection and whether it can pass the time required by the salt spray. Tools include environmental testing machines and salt spray testing machines. In short, in the production and sales process of cross recessed screws, there must be necessary tools to detect the quality of screws. The summary should be summarized as follows: calipers, hardness testers, salt spray machines, environmental testing machines, pass and stop gauges, etc. .

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