The Sharpness of Blades: Napping vs. Modern Grinding Methods

TLDRThis video compares the sharpness of napped obsidian edges with modern grinding methods, using a hair-splitting experiment. It also explores the effectiveness of hand ground woodworking chisels and tests the sharpness of flint and obsidian. Results show that obsidian is incredibly sharp but too brittle for practical use.

Key insights

🔪Napped obsidian has been claimed to produce the sharpest edge known to humankind.

🔨Hand ground woodworking chisels are commonly used for precise cutting in woodworking.

💎Obsidian, a volcanic glass, is known for its ability to fracture into extremely thin and sharp edges.

📏A Bess certified sharpness tester can measure the maximum force required to slice through a wire and quantify sharpness.

🔬Atomic Force Microscopy (AFM) can be used to measure the edge radius of blades and confirm sharpness.

Q&A

Is napped obsidian the sharpest material for creating fine edges?

—Yes, napped obsidian has been claimed to produce the sharpest edge known to humankind.

Are hand ground chisels effective for precise woodworking?

—Yes, hand ground chisels are commonly used by woodworkers for accurate cutting and creating precise joints.

What makes obsidian edges so sharp?

—Obsidian is a volcanic glass that can fracture into extremely thin and sharp edges, making it ideal for cutting.

How can sharpness be quantified?

—Sharpness can be measured using a Bess certified sharpness tester, which measures the maximum force required to slice through a wire.

How can the edge radius of blades be measured?

—The edge radius of blades can be measured using Atomic Force Microscopy (AFM), which involves scanning a probe over the surface of the blade to determine its shape.

Timestamped Summary

00:00Napping is an ancient process used to create sharp edges on flint and obsidian.

02:15Napped obsidian has been claimed to produce the sharpest edge known to humankind.

03:10Hand ground woodworking chisels are commonly used for precise cutting in woodworking.

04:12Obsidian, a volcanic glass, is known for its ability to fracture into extremely thin and sharp edges.

06:36A Bess certified sharpness tester can measure the maximum force required to slice through a wire and quantify sharpness.

10:32Atomic Force Microscopy (AFM) can be used to measure the edge radius of blades and confirm sharpness.

11:38Brilliant.org offers courses to learn maths, data science, and computer science interactively.

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