Fasteners are small, but they play a huge role. The use of fasteners requires regular maintenance to ensure the safer use of fasteners, and can prolong the service life of fasteners and improve the performance of mechanical equipment.

When we maintain fasteners, there are three main problems:

1. When quenching fasteners, we should use silicate detergent to clean up the impurities on the fasteners, and then rinse them carefully to avoid the residual impurities on the fasteners and affect their normal application.

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2. The color of fasteners may change after tempering treatment. After soaking fasteners in ether for a period of time, oily substances will be produced, which indicates that fasteners are not clean enough. After analysis, it will be found that the stacking of fasteners during heating is not very reasonable, and there may be some minor oxidation phenomenon in quenching oil. Blind hole nut

3. If there is a white substance on the fastener, it may be some phosphide. The reason for this phenomenon is that the acid cleaner is not used for cleaning, and the inspection of the rinsing tank is not careful enough.

These problems must be paid attention to, which will directly affect the performance of fasteners, and may also lead to the shortening of the service life of fasteners, resulting in the phenomenon of early rise and damage of fasteners, etc. Twill nut

The most important link in the development and design of fasteners is the quality control. There are several major ports from feeding to finished product delivery, which have different inspection methods. First of all, feeding is related to appearance, size, elements, performance, harmful substances detection, etc. In the process, more is appearance, size, knock test, forging streamline; heat treatment is more appearance, hardness, torque, tension, metallography, etc. Surface treatment is more hydrogen embrittlement test, coating, salt spray, etc. Including that the shipment has a harmful substance detection. In size and appearance detection, the common ones are quadratic element, profilometer, coordinate measuring instrument, image sorter (this is a complete sorter); in mechanics and chemistry detection, there are mainly hardness machine (Lowe and Vickers), tension machine, metallographic microscope; in material detection, there is a spectrum analyzer, salt spray test machine.