Look at the edges of an axe. What do you see? If you said an inclined plane, you’d be on the right track. Wedges are similar to inclined planes, but there are some differences. An axe is actually two inclined planes put together. An inclined plane and a wedge have completely different purposes.

An inclined plane is generally used to move something from one place to another, e.g., ramps or stairs. Wedges are used to separate objects or to hold objects in place. Confused? Read on for some examples.

Wedge Facts For Kids

  • A wedge is a simple machine.
  • It’s a type of inclined plane.
  • Used to split or cut objects.
  • Converts force into a splitting action.
  • Has a thin edge and a wide base.
  • Increases force efficiency.
  • Common in axes and knives.
  • Reduces the effort needed for tasks.
  • The oldest known wedge is from 8000 BC.
  • Also used in doorstops and chisels.

Simple machines

Simple machines, such as the wedge, are essential tools that simplify our work by making it easier. The wedge, a unique simple machine, operates by separating materials into two parts when pushed into something.

This characteristic is evident in everyday objects such as axes, nails, and doorstops, which are all common examples of wedges. For instance, an axe is used for splitting wood and a knife for cutting food, highlighting the functional design of the wedge. Intrinsically, a wedge is composed of two inclined planes, another kind of simple machine, merged together.

Thus, the wedge, as a simple tool, exemplifies the application of science and engineering in the most basic objects that are integral to our daily lives.

Inclined plane

A wedge, a fundamental tool in our everyday lives, is effectively a mobile inclined plane, or to simplify it further for children, imagine it as a movable slope. Its function, much like an inclined plane, is to alleviate the amount of force we need to exert, making our tasks less strenuous. When observed closely, a wedge resembles two back-to-back inclined planes.

A prime example of this simple machine is a doorstop, which we commonly utilize to keep a door ajar. The doorstop operates by transmuting the downward force exerted on it into two sideways forces.

The efficiency of a wedge is determined by its sharpness or length, with a sharper or longer wedge requiring less applied force. Therefore, the significance of wedges and inclined planes lies in their ability to significantly enhance our efficiency in performing various tasks.

Mechanical advantage

A wedge, one of six simple machines, serves to enhance human mechanical advantage, facilitating tasks more efficiently and quickly by transforming applied force into a splitting force that acts perpendicularly to the wedge’s edge.

Take a door stopper, for example, it’s a type of wedge where the exerted force from pushing it under the door is divided into two forces directed downwards and sideways, consequently halting the door’s movement.

Hence, by enabling us to accomplish more work with less effort, a wedge significantly boosts our efficiency and productivity.

Force and pressure distribution

A wedge, a simple machine that alters the application of force, provides an excellent educational tool for children to comprehend the principle of force and pressure distribution. Essentially, when a force is applied on the wider end of the wedge, it is dispersed over a larger area, thus decreasing the pressure.

Conversely, the same force applied on the slimmer end is concentrated over a smaller area, intensifying the pressure. This pressure differential enables the wedge to slice or separate objects with minimal effort. For instance, consider a doorstop, which is a form of a wedge.

The force exerted when the doorstop is pushed under a door is distributed and magnified at the slim end, effectively keeping the door in position. This illustrates the practical application of a wedge in manipulating force and pressure to simplify tasks.

Carpentry and woodworking tools

In the context of carpentry and woodworking, wedges play a crucial role in familiarizing children with these crafts. They serve as a fundamental component in various woodworking tools, including axes, chisels, and hand saws.

For instance, an axe, which is essentially a wedge, facilitates the splitting of wood by focusing force on a minimal area. Chisels, another embodiment of wedges, are instrumental in carving or cutting hard substances like wood, due to the force applied at their thin edge.

Similarly, the teeth of hand saws exemplify tiny wedges, designed to penetrate the wood during the push-and-pull action. Overall, wedges significantly simplify woodworking tasks by minimizing the effort necessary for shaping or cutting wood.

Metal splitting and cutting

Wedges, the simple machines that are particularly advantageous in metal splitting and cutting, can be likened to a very sharp triangle for children’s understanding. When force is applied to its broad end, it cuts or splits the material it is pushed into, making it an essential tool in metalwork.

Metal, being robust and hard, is difficult to cut or split, but the unique sharp design of a wedge concentrates the applied force into a small area, simplifying the process. Therefore, tools such as axes, knives, and chisels, which are all examples of wedges, are frequently utilized in metalworking.

Geometrical shape and design

Wedges, intriguing geometric shapes, serve a significant role in design and everyday life, doubling as critical components in various mechanical devices. Often made of hard materials like metal or wood, a wedge is a triangular-shaped tool in practical applications, while in geometry, it takes on a three-dimensional form with five faces.

These include a triangular base and rectangular sides, a unique design that allows it to either secure objects in place or split them apart. A common example is the wedge-shaped doorstop, used to keep doors open. The simplicity and effectiveness of the wedge’s design, with its broad base tapering to a sharp edge or point, enable it to alter the direction of a force.

Consequently, this makes tasks like cutting, splitting, tightening, securing, or adjusting objects much easier. Therefore, the wedge is a testament to the brilliance of geometric design.

Physics of levers

A wedge, a simple machine operating similarly to a movable inclined plane, is typically utilized to separate or lift objects or to keep them stationary. The physics behind its operation involves the transformation of force applied at its blunt end into forces perpendicular to its inclined surfaces.

This concept is akin to the functioning of another simple machine, the lever, which amplifies the applied force. By conceptualizing a wedge as a lever, with the pointed end serving as the fulcrum or pivot point and the force being exerted at the opposite end, one can better comprehend the physical principles underlying its operation.

Thus, analogous to a lever, a wedge serves to amplify the force, thereby simplifying tasks such as cutting or lifting.

Material properties and strength

Wedges, fascinating tools utilized since ancient times, serve as an exemplary demonstration of the critical role material properties and strength play in their effectiveness. Fabricated from robust materials like steel or hard plastics, wedges are designed to withstand immense force when employed to split, lift or secure objects.

The strength of these materials is paramount in preventing the wedge from breaking or deforming under pressure. The unique design of a wedge, characterized by a pointed end that gradually broadens, is intentionally created to amplify the applied force, thereby simplifying tasks.

Nevertheless, the durability and toughness of the material also dictate the sharpness of the wedge without risking the tip’s breakage. Thus, a comprehensive understanding of material properties and strength is indispensable to comprehending a wedge’s functionality.

Historical uses in construction and engineering

Wedges, a pivotal tool throughout history, have been especially crucial in the realms of construction and engineering. Their historical significance can be traced back to ancient civilizations such as the Egyptians, who employed large wooden wedges to fracture stones when building architectural marvels like pyramids.

Further, their application extended to the fabrication of wheels and axles, the core elements in primitive engineering. The construction of iconic Roman roads and aqueducts, still celebrated as extraordinary engineering achievements, also heavily relied on the use of wedges.

Despite the evolution of technology, the wedge, in its simplicity and power, continues to be an indispensable tool in modern construction and engineering, underlining the enduring effectiveness of some of the simplest tools.

Fun Facts

  • An axe is a wedge used to chop – or break – logs into pieces.
  • A shovel is a wedge used to break up soil.
  • A knife is a wedge used to cut food or other material.
  • A push pin or tack is a wedge used to hold papers in place.
  • A nail is a wedge used to secure two boards together.
  • A doorstop is a wedge used to hold a door open.



  1. Wedge: a simple machine used to separate or hold together materials
  2. Separate: divide, tear, or move apart
  3. Secure: hold in place; make stable


Questions and Answers

Question: Who invented the first wedge?

Answer: We’re not sure, although it seems to have been around for a long time. Arrowheads are a type of wedge. Chisels used for sculpture are also a form of wedge. Early humans probably developed primitive axes to chop wood.


Learn More
Visit PBS and Idaho Public Television for a video on simple machines and wedges.