Product quality is the lifeline of an enterprise, directly affecting its survival and development. Even if the product design is reasonable and the equipment is advanced, unqualified products still exist. Therefore, quality inspection of products is very important. As one of the widely used components in production, screws are widely used in high-performance products in high-tech fields such as aviation and aerospace, as well as in many fields of daily life. Due to complex usage conditions, screws are influenced by many factors.
The surface inspection of screws can be divided into two situations: one is the inspection before electroplating the screws, including dimensions, tolerances, and other aspects to ensure compliance with national standards or customer requirements; The second is the inspection after screw electroplating, mainly checking the color of the coating and whether the surface is good.
1. Check if the color and material of the screws meet the requirements.
2. The surface of the screw should not exhibit any abnormal phenomena such as burrs, deformation, damage, or poor processing.
3. The surface coating of screws should be uniform, without any abnormal phenomena such as oxidation, rust spots, poor coating, paint peeling, etc.
4. Check if there are any abnormal phenomena such as mixed installation of other screws, inconsistent lengths, and missing accessories.
For the performance testing of screws, including tension, torque, hardness, penetration, corrosion resistance, etc. The corrosion resistance test can be verified through a smoke test, which involves placing screws in a smoke box for 24 hours, then removing them for cleaning and drying, and observing whether rust occurs within 24 hours.
With the rapid development of industry, screws often cause safety accidents due to external loosening during industrial use. Therefore, people are increasingly valuing safety and anti loosening measures.
There are three commonly used anti loosening methods for screws: friction locking, mechanical locking, and permanent locking. Among them, mechanical locking and friction locking are called detachable locking, while permanent locking is called non detachable locking.
Mechanical anti loosening methods include using split pins, anti loosening washers, threading steel wire ropes, etc. Mechanical anti loosening methods are reliable, and it is recommended to use mechanical anti loosening methods for important connections.
Friction anti loosening includes the use of gaskets, nuts, anti drip glue, etc. Anti drip adhesive is a layer of adhesive applied to the screw threads, which has excellent properties such as high adhesion and non toxicity. Apply anti drip adhesive to stainless steel non-standard screws, and after drilling, it has super strong adhesion, which can make the screws have super strong fastening effect after the nut and screw are combined or the product thread hole is connected, achieving good anti loosening effect.
