Brief description

A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six classical simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place.

Use / Function

• Splitting: Separating wood (axes, splitting wedges) or stone.
• Cutting: Knives, chisels, and scrapers are sharp wedges.
• Lifting: Raising heavy objects slightly to insert rollers or levers.
• Holding: Doorstops or shims to prevent movement.

Operating principle

The wedge functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width.

How to create it

1. Shape: Cut or forge a piece of hard material into a triangular prism.
2. Sharpen: Grind the thin edge to a sharp point or blade.
3. Harden: If using metal, temper the edge to hold its shape.

Materials needed

• Wood: Hardwood for temporary wedges or splitting soft materials.
• Stone: Flint or obsidian for cutting tools.
• Metal: Iron or steel for durability and sharp edges.

Variants and improvements

• Axe: A wedge on a handle.
• Chisel: A narrow wedge for precision cutting.
• Nail: A pointed wedge for fastening.

Limits and risks

• Friction: High friction can make the wedge stuck.
• Bounce: If the angle is too wide, the wedge may pop out when struck.
• Shattering: Brittle materials can shatter under the impact force used to drive the wedge.