A nylon screw is a type of fastener used for making mechanical connections, between mating objects, to ensure that they are held together securely. These screws are commonly used in small home appliances, consumer electronic devices, and to secure many other objects. It is important to select the right size and type of nylon screw for each specific application.
A nylon screw is tightened directly into a threaded or tapped hole, and can be used with or without a nut. It has a large head on one end, and features a cylindrical shaft with an external thread — a helical structure that allows the screw to be advanced when rotated. The tapped hole or nut has an internal thread that matches the external thread of the screw. When a nylon screw is inserted and rotated into a tapped hole or nut, the screw advances. The screw is tightened and loosened by applying torque to the head, using a tool.
Examples of commonly used nylon screws are the hex head, which has a hexagonal shape for use with a spanner wrench; the socket head, which has a recessed hexagonal hole for use with an Allen wrench; and the slotted head, which has a dome-shaped head with a recessed slot, to allow a screwdriver to be used. The large diameter head provides a positive mechanical stop when tightening the screw, and allows the head to be shaped to accept a specific type of tool.
Nylon screws are available in both English and metric sizes, and with a wide variety of coarse and fine threads. The type and size of nylon screw selected for a particular application depends primarily on the amount of force required to adequately secure the mechanical connection. A nylon screw will generate a clamping force when tightened, but the amount of clamping force is limited, due to the material strength properties of nylon. For this reason, nylon screws are generally smaller in size and are not usually used for large scale or heavy-duty fastening.
These items are generally lightweight, tough, resistant to corrosion, and have good electrical insulating properties. They conform easily to irregular surfaces and provide limited vibration dampening. Nylon will absorb moisture from its environment, which can cause a large fluctuation in its dimensions. This should be considered when selecting a nylon screw, particularly in fastening applications where a change in the screw dimensions could adversely affect the integrity and functionality of the mechanical connection.
