Many other fasteners are driven or hammered into place, but due to the threading of the screw, this type of fastener cannot be fastened effectively with hammering or pounding. Instead a screw is twisted, so that the threads slide into the material, keeping the fastener from being pushed or pulled out of place.
Some screws are designed to work independently of other pieces of hardware. These screws are typically used with softer materials, like wood, so that the screw can cut grooves in the material as it is inserted. On the other hand, other screws are paired with an internal thread which contains a complimentary threading pattern that allows the screw to be inserted without cutting grooves in the material.
Due to the diversity of fastening needs and applications, screws also come in a huge variety. Examples of different screw types include machine screws, self-tapping screws, drywall screws, wood screws, hex cap screws, and self-drilling screws.
Each of these screws is designed to offer particular advantages for use in specific applications. Self-tapping screws can be inserted into untapped holes. Wood screws have a sharp point to start threading the screw into wooden pieces and are partially unthreaded near the head of the screw to allow the head to be flush with the surface of the wood. These are just a small number of examples of different types of screws and their designs.
Many screw manufacturers can work with customers to design screws to fit unique requirements or challenging applications. Essentially every component of the screw can be customized: the diameter of the screw, the head type, the end type, and even the distance between threads.
However, a customized screw will usually cost much more than a standard screw. Most manufacturers will have a diverse inventory of standard screws to meet essentially any application.