Screws are indispensable industrial necessities in daily life, such as cameras, glasses, clocks and watches, electronic products, etc. , using micro screws; Universal screws for TV sets, electrical products, musical instruments, furniture, etc.

As for projects, buildings and bridges, large screws and nuts are used; Transportation equipment, airplanes, trams, cars, etc. There are both large and small screws. Screw plays an important role in industry. As long as there is industry on the earth, the role of screws will always be important.

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Industrial application

The main purpose is to make industrial products form a fixed whole. In use, it often happens that the teeth can't fit tightly, the screw head will fall off if the teeth are locked too hard, or the tooth line is not tightly locked, which can't meet the use conditions, all of which are quality and accuracy problems. Screw is a "measure", not a hand-made work of art, in mass production, the purpose is to achieve high-precision and stable quality and popular price for consumers.

Generally, the screw accuracy is 6g (Grade 2, the American specification "IFI" is 2A tooth), and the thick screw used in construction engineering is 8g (Grade 3, "IFI" is 1A tooth). The value of screws is very important, and there are examples of automobile factories closing down because of poor quality screws in the world; There are also examples of plane crashes and vehicle subversion caused by poor quality of screws.

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