What is a Shim?

The term shim has come to take on a number of different meanings. From the rectangular wedge shims used behind hinges in construction to the round shims that adjust pinion depth, these simple devices can be found almost anywhere and come in numerous shapes and sizes. Generically, a shim can be described as a simple item placed between other objects in order to bring the objects to a desired level. Using this definition as a guide, we can now look at more specific examples of shims in the everyday world.

Shims play a significant role in carpentry and construction. They are most often used when a piece of a lumber needs to be aligned with another, in which case the shim is placed both in a gap and against the piece to bring it to the correct position. This is most commonly seen when constructing door jambs and mounting windows, but also occurs in other areas, including cabinet installation and some stair fittings.

Another type of shim is the type used to bypass locks. Numerous sources on the Internet explain how to take a small piece of aluminum from a soda or beer can and use it to create a shim that will compromise padlocks. A shim can also be used to take advantage of imperfections in other types of locks, the concept being that the shim slides into an opening and pushes part of the locking mechanism out of the secured position.

Shims also play roles in numerous other areas, both simple and complex. Shims are used to help align pipes in plumbing. Masonry shims are usually just stones used to prop up rocks or large bricks. Specially designed shims are used to separate heat sinks from CPUs in computers. Shims are used for numerous different aspects in engines. In sport fencing, shims are even used to test distances in electrical weapons to make sure that they meet competition specifications.

Shims can be made from many different materials, depending on their purpose. Shims used in carpentry are often made of wood similar to what the shim will be supporting, but plastic and various types of recycled material shims are also used. Those used in masonry tend to be pebbles or stone wedges. Shims used near heat are often made of heat-resistant materials, while those used near electricity are non-conductive in most cases. Shims used for testing purposes may be required to conduct electricity to be effective.

The term shim has also come to have numerous new and slang meanings. For instance, a shimmy is a type of simple dance. Computer coding workarounds are sometimes called shims. The term shim also comes up when it comes to imaging, both in magnetic resonance imaging (MRI) and more traditional areas.