Brief description

A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal by hand, struck with a mallet, or applied with mechanical power.

Use / Function

• Woodworking: Carving joints (mortise and tenon), shaping wood, woodturning on a lathe.
• Masonry: Cutting and shaping stone bricks or sculptures.
• Metalworking: Cutting cold metal (cold chisel) or removing waste material.

Operating principle

The wedge shape of the blade concentrates force onto a small area, splitting or shearing the material. When used with a lathe, it acts as a fixed cutting point against a moving surface.

How to create it

1. Forging: Heat a metal rod (iron or steel) until malleable.
2. Shaping: Hammer one end flat to create a blade.
3. Hardening: Heat the blade to critical temperature and quench it (water or oil) to make it hard.
4. Tempering: Reheat gently to reduce brittleness.
5. Sharpening: Grind the edge to a precise angle (25-30 degrees for wood).
6. Handle: Fit a wooden handle to the other end for grip and to absorb shock.

Materials needed

• Blade: High-carbon steel (best), iron (needs frequent sharpening), or flint/obsidian (primitive).
• Handle: Hardwood (ash, hickory) or bone.

Variants and improvements

• Gouge: Curved blade for carving hollows.
• Skew Chisel: Angled blade for smooth finishing on a lathe.
• Cold Chisel: Thick, tempered for cutting metal.

Limits and risks

• Dulling: Requires frequent sharpening to work effectively and safely.
• Chipping: If the steel is too brittle (bad temper), the edge will chip on hard knots.
• Safety: Always cut away from the body. A dull chisel is more dangerous than a sharp one because it requires excessive force.