The wedge is a basic machine with a wide variety of uses. One of the six classic simple machines, the wedge can be used to divide an object into two pieces, make lifting easier or keep an object in place.
A wedge is an inclined plane with one side lying on a surface. It takes the shape of a triangle and is portable and useful in a wide array of tasks. The sharp tail-end of the wedge serves as a point of balance as well as a basic cutter, while the inclined sides send the force from the base to the tip in order to execute a particular action. The strength of the wedge can be measured by defining the ratio of its slope to its width.
Although its exact history is unknown, the wedge has been around for more than 9,000 years. Some of the oldest wedges were used in ancient Egyptian quarries and made of bronze. These wedges were used to break stone blocks to construct palaces and pyramids. Wooden and antler wedges were used by Native Americans for splitting and shaping wood to make dwellings, accessories and canoes.
While primarily used for splitting objects, wedges can also be used in lifting heavy items from the surface they lie on. They are also helpful in moving objects such as stone blocks. Mauls and wedges are also made to split wood. Narrow wedges with long tapers are called shims, and they are usually found in carpentry and woodwork shops. Wedges, depending on their length, can also hold objects into place, but only for a limited time.
Through the years, wedges have undergone various renovations to cater to increasing needs. Wedge-type doorstops have been developed based on the original wedge concept and wedges have also been highly useful in poppet valves and bicycle parts such as stems and eccentric bottom rackets.
The power of the wedge can be measured in terms of its mechanical advantage, and it is calculated by dividing the wedge’s slope by its width. A more narrow, or acute, wedge angle has greater mechanical advantage, particularly when it is made of steel or iron. The power of the wedge, however, can be reduced when it is made of more elastic material such as wood because of decreased friction.