Screws, known as "the rice of industry", are indispensable in the manufacturing of everything from large-scale aircraft, automobiles, and airplanes to small items such as glasses, mobile phones, tables, chairs, and benches. Screws are also called "screws", which is a general term for screws and screw rods. However, it should be noted that screws and screw rods are actually different. Screws are also called wooden screws, with pointed tips at the front and a larger pitch. They are generally used for fastening wooden and plastic parts. Screw rods have flat tips at the front, with a smaller and more uniform pitch. They are usually paired with nuts and are used for fastening metals and machine components.