A screw is a threaded fastener that is used to attach items or help keep them in position. Most screws have a head designed to fit a certain type of screw driver, which allows users to insert or remove the screw. A stripped screw is one on which the head is damaged and, thus, difficult or impossible to turn using conventional methods. This damage can occur through normal wear and tear or by using the wrong type of driver for the screw. Using an electric screwdriver can exacerbate this issue by damaging the head more quickly.
Screws have several types of head designs, depending on the manner in which the screw is intended to be used. Some heads are more susceptible to stripping than others, particularly when being driven by machine-guided tools. The simplest and least expensive screws often are manufactured with slot heads, which can be driven with a variety of tools. These types of heads also are easily damaged if too much torque is applied, often leading to a stripped screw. Some modern screw designs, such as the Phillips head, are designed to allow the driver to slip out of the head before damage occurs.
Other types of screw heads have multiple slots that help keep the driver in place and prevent the screw from being easily stripped. Advances in materials technologies have led to tougher screws intended to hold up better under high torque. Combined, these features have led to more efficient manufacturing and less potential for damage to products as the result of a stripped screw.
In many environments, screws have a tendency to corrode over time. When exposed to moisture, they may rust or accumulate heavy water deposits that can lead to damage during removal. It is important for users to inspect a screw for corrosion and choose the right driver for the head before attempting to remove it. Using a driver that is the wrong size or designed for a different type of screw head can lead to stripping — and possible personal injuries.
When a screw does become damaged, a user can attempt several methods to remove the stripped screw. If the screw is made from a softer metal, then the user can try cutting a new slot in it with a rotary tool or removing the head of the screw with a power drill. A product called a screw extractor can help users remove a pesky stripped screw. One should always use caution when using power tools on metal objects and wear eye protection to avoid injury.