While all wedges share a similar triangular geometry, they are categorized based on their specific application and the way they redirect force.
1. Cutting Wedges
These are most common types of wedges. They feature a sharp edge designed to penetrate a material and force it apart by breaking the molecular bonds of the object.
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Examples are Axes, knives, scissors, and chisels.
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Sharp edge concentrates the input pressure onto a tiny surface area, making it easier to overcome structural integrity of the material (like wood or meat).
2. Splitting Wedges
Splitting wedges are generally thicker than cutting wedges. They are used to drive a deep rift into a material.
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Examples are log splitters or stone-splitting wedges.
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Once initial cut is made, increasing width of wedge provides lateral force necessary to push the two sides of material away from each other until they fracture.
3. Lifting Wedges
Instead of separating a single object into two, a lifting wedge is driven under an object to raise it.
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Examples is shims used for leveling furniture, heavy-duty hydraulic wedges used in construction, or even a simple doorstop.
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Wedge converts horizontal motion into vertical lift. Because slope is gradual, a person can lift a very heavy load (like a heavy cabinet) with relatively little horizontal pushing force.
4. Securing (Friction) Wedges
These wedges are used to hold objects in place through use of high friction.
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Examples: A door wedge, a nail, or a tapered plug.
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When driven into a gap, wedge exerts a strong normal force against surrounding surfaces. This increases the frictional force to a point where the wedge (and the object it is securing) becomes difficult to move.
Comparison of Wedge Applications
| Type | Primary Goal | Example | Force Direction |
| Cutting | Severing material | Knife | Vertical to Lateral |
| Splitting | Deep separation | Log Wedge | Vertical to Lateral |
| Lifting | Raising a load | Shim / Jack | Horizontal to Vertical |
| Securing | Immobilizing | Doorstop | Friction-based |