Screw, also called "screw" [Screw], "screw" (screw).

The screw is a tool that uses the physical and mathematical principles of the inclined plane circular rotation and friction force of the object to tighten the parts step by step.

Screw is a common term for fasteners and a daily mantra. Screws are an indispensable industrial necessity in daily life:

Small screws such as cameras, glasses, clocks, electronics, etc.; General screws for TV, electrical products, Musical Instruments, furniture, etc.;

For projects, buildings and Bridges, large screws and nuts are used; Transportation equipment, aircraft, trams, cars, etc., are used for large and small screws.

Screws have important tasks in industry, and as long as there is industry on Earth, the function of screws will always be important.

Screws are a common invention in people's production and life for thousands of years, and according to the application field, it is the first major invention of mankind.

The function of the screw is mainly to connect the two workpieces together and play a fastening role, so the screw manufacturer is produced.

The first person to describe spirals was the Greek scientist Archimedes (circa 287-212 BC).

The Archimedes spiral is a giant spiral inside a wooden cylinder used to lift water from one level to another to irrigate fields.

The true inventor may not have been Archimedes himself. Maybe he's just describing something that already exists, using another tool or hand to twist a screw.

It may have been designed by skilled craftsmen in ancient Egypt to use irrigation from both sides of the Nile.

In the Middle Ages, carpenters used wooden or metal nails to connect furniture to wooden buildings.

In the 16th century, nailmakers began to produce nails with spirals, which were able to connect things more firmly.

That is a small step from this kind of nail to the screw, so later gradually invented the screw.

Around 1550 AD, the first metal nuts and bolts appeared as fasteners in Europe, and the American standard 1/4 screws were handmade on a simple wooden lathe.

The screwdriver (screw chisel) appeared in London around 1780. Carpenters found that using a screwdriver to tighten screws held things in place better than using a hammer,

This is especially true when it comes to fine grained screws. In 1797, Maudsley invented an all-metal precision screw lathe in London. The following year Wilkinson made a nut and bolt making machine in the United States.

Both machines produce universal nuts and bolts. Screws were quite popular as fixed parts because an inexpensive method of production had been found.

In 1836, Henry M. Philips patented a screw with a cross grooved head, which marked a major advance in screw base technique.

In order to standardize the screw specifications, each country now has a corresponding screw metric table.

Unlike traditional slotted nail head screws, the cross slotted head screws have the edge of the cross slotted nail head screw head. This design makes the screwdriver automatically centered and not easy to slip off, so it is very popular.

Universal nuts and bolts can join metal parts together, so by the 19th century, manufacturing machines to build houses of wood, metal bolts and nuts have been replaced.

Now the role of the screw is mainly to connect the two workpieces together, play a fastening role, screws are used on general equipment, such as mobile phones, computers, cars, bicycles, all kinds of machine tools, equipment, almost all machines need to use screws.

Screws are indispensable industrial necessities in daily life: such as tiny screws used in cameras, glasses, clocks, electronics, etc.; General screws for TV, electrical products, Musical Instruments, furniture, etc.

Screws commonly used head types are: a word, cross, cross, hex, hex, flat head, round head, square neck, oval, etc., screw surface treatment has dacromet, galvanized, passivation, electrophoresis, blackening and so on.

The main categories include ordinary screws, machine screws, self-tapping screws and expansion screws, combination screws and so on.