Screws are tools that utilize the physics and mathematical principles of circular rotation on an inclined plane and friction to progressively secure parts of machinery. The term "screw" is a general expression for fasteners and is commonly used in everyday speech. Screws are an indispensable industrial necessity in everyday life: from small screws used in cameras, eyewear, watches, and electronics to general screws used in televisions, electrical appliances, musical instruments, and furniture; to large screws and nuts used in engineering, construction, and bridges; and to a combination of various-sized screws used in transportation devices, aircraft, trams, and cars. Screws are a common invention in people's production and life over thousands of years, and, according to their application fields, they are one of the great inventions of mankind.
































