The wire of the screw is the basis for determining the quality of the mobile phone screws. The wire is not good, even if the production equipment is advanced and the staff is skilled, it is impossible to produce high-quality mobile phone screws. Secondly, look at the quality of mobile phone screws from the overall aesthetics of mobile phone screws. A mobile phone screw is formed, the size of the head of the screw, the superiority of the appearance of the flat gasket, whether the screw thread can pass through the stop rule, and so on.

These need to be detected. A good mobile phone screw, its overall standard can meet the requirements of national standards, or customer requirements. Then look at the quality of mobile phone screws from the electroplating color. Of course, iron mobile phone screws need to be electroplated, but stainless steel mobile phone screws do not. Many of them are passivation, in order to increase the salt spray resistance of stainless steel mobile phone screws. The electroplating color of the mobile phone screws is not well controlled, which will produce a large color difference. This is not so good-looking.

Intensity grades Many national standards are divided into intensity grades. Mobile phone screws are no exception. The strength grades of mobile phone screws are divided according to the material of the screw wire and the hardness index of the screw wire. Generally, the materials of mobile phone screws are divided into stainless steel and iron, and stainless steel is divided into stainless steel 201, stainless steel 304 and stainless steel 316. There are three types of iron: low-carbon steel, medium-carbon steel, and high-carbon steel.

In short, there are many kinds of standard grade strength of mobile phone screws, but generally only two are used in the market, one is the 4.8-level mobile phone screw strength, and the other is the 8.8-level mobile phone screw strength. 4.8 grade mobile phone screws are widely used in the market in terms of customer demand. In terms of the standard strength of 8.8 grade mobile phone screws, we generally refer to grade 8.8 inner hexagonal mobile phone screws, grade 8.8 pan-head mobile phone screws, and grade 8.8 outer hexagonal mobile phone screws. These three are more commonly used.