Screws are commonly known as "screws" with external threads.
The shape of the nut is usually hexagonal, and the inner hole is internally threaded. It is used to match the bolt and close the relevant parts.
The nut is a common name and the standard should be called "nut".
The head of the bolt is generally hexagonal and the stem has external threads. There are all silk, half silk, it is best to code according to the national standard.
The screw is small, the head has a flat head, a crosshead, etc., and the stem has external threads.
The stud should actually be called “double stud”, with external threads on both ends, and the middle is usually a polished rod. The long end of the thread is used to connect to the deep hole and the short one is connected to the nut.
Screws are a rather general statement.
The exact statement should be bolts, screws, and screw caps.
Bolts and screws are round elongated objects with equally spaced threads.
The bolts are of flat head cylindrical shape; the screws are pointed at the front like nails.
Bolts must be used with screw caps or on items that have been threaded.
Screws are used on softer or thinner objects, and use their own threaded edges to drill forward.
The threads on the bolts are shallow and have no sharp edges; the threads on the screws are sharper and the threads are deeper, which facilitates drilling into the object.
Most bolts and screws require a simple tool that is most commonly used - a screwdriver.