📝 Article 2: The Perfect Angle – Mastering Sharpening Angles (15° vs 20°)

Which Sharpening Angle to Choose: A Complete Guide 15° vs 20° (Japanese and European Knives)

📐 Introduction: Why the Angle is the Master of the Cut

In Article 1, we established that the edge is the cutting edge and the bevel is the surface leading to this edge. The sharpening angle is the measure of the opening of this edge (including the angle). If sharpening is the fundamental action, then the angle is the guiding principle of this action.

Choosing and, above all, maintaining the correct angle is what separates a mediocre knife from a surgical cutting instrument. A poorly chosen or inconsistently maintained angle negates all your sharpening efforts.

We will decipher the two global standards (15° and 20°) and explain how the consistency of this angle is the real secret to a lasting cutting edge.

1. Understanding the Included Angle vs. the Working Angle

Before discussing figures, let's clarify the essential terminology:

• The Working Angle (or Lateral Angle): This is the angle at which you hold the blade on the stone or sharpener. For example, 10° or 20°.

• The Included Angle (or Total Angle): This is the angle of the "V" formed by the meeting of the two bevels. On a symmetrical knife, the included angle is twice the working angle.

  • Example: Working angle of 20° on each side = Included angle of 40°.

To simplify, in knife making, when we say a knife is sharpened to "20 degrees," we are generally referring to the lateral working angle. In this article, we will use this convention.

2. The Clash of Standards: 20° (European) vs 15° (Japanese)

Choosing the angle is a constant compromise between cutting precision and blade durability . The more acute (small) the angle, the finer and more precise the cutting edge; the more open (larger) it is, the more resistant it is to impacts and wear.

2.1. The European Standard Angle: 20° (Angle Included: 40°)

The standard for Western knives (Solingen, Thiers, etc.) is traditionally a 20° working angle (i.e., 40° inclusive).

• Benefits :

  • Durability: The 40° angle is robust and resistant. It better supports hard cutting boards (glass, ceramic) or less delicate uses.

  • Less maintenance: The wire is less likely to roll or chip, requiring less frequent sharpening.

• Use: Versatile chef's knives, bread knives, carving knives (meat).

2.2. The Japanese Standard Angle: 15° (Angle Included 30°)

Modern Japanese knives (Santoku, Gyuto) and high-end knives are often designed for a 15° working angle (i.e., 30° inclusive).

• Benefits :

  • Unrivaled Cutting Fineness: The cutting edge is much finer. It penetrates food with minimal resistance, offering a "razor-sharp" feel.

  • Precision: Ideal for fine cutting, slicing and delicate preparation of sushi or vegetables.

• Disadvantages:

  • Increased fragility: The thin wire is more delicate. It can be damaged quickly if you cut bones, frozen food, or if you use the wrong technique.

• Uses: Vegetable knives ( Nakiri ), fish knives ( Yanagiba ), Japanese chef's knives (Santoku).

3. When to Use Other Angles

It is important to note that these angles are not fixed. Some professionals choose specific angles for particular tasks:

• Ultra-fine angles (10° to 12°): Reserved for filleting knives, paring knives, or razors. The steel must be very hard to withstand such fineness.

• Wide angles (25° to 30°): Used for tools requiring maximum robustness, such as meat grinders, machetes or knives intended for cutting bones.

4. The Mistake That Ruins Your Edge: Angular Irregularity

You've bought a sharpening stone, you're using the right method, but your knife remains "soft"? The problem is almost always the same: the inability to maintain a constant and precise angle .

4.1. The Problem of Hands-Free Movement

When sharpening freehand (on a stone or with a honing steel):

1. Constant Angle Change: Your wrist and arm cannot guarantee the same angle (e.g., 15°) along the entire length of the blade and for each stroke. The heel might be at 18°, the middle at 22°, and the tip at 15°.

2. Creating a Rounded Edge: These variations do not remove material where it is needed, but they "round" the wire instead of forming a flat and clean bevel.

3. Result: A cutting edge that lacks "bite", because the two bevels do not meet perfectly.

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4.2. The Solution: Consistency Assurance

This is where modern tools come into play, and it's a key point for guiding your e-commerce:

Guided sharpening systems (notably diamond roller sharpeners) and fixed-angle systems were designed specifically to eliminate this human error . By mechanically fixing the angle (e.g., 15° or 20°), they ensure that the abrasive works at the exact angle, from the beginning to the end of the pass, along the entire length of the edge.

For beginners or amateurs, achieving consistent angle accuracy is impossible without a guide tool. Angle consistency guarantees performance and is intrinsically linked to the tool's simplicity.

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5. 🗃️ Summary: Angles and Uses

✨ Conclusion and Next Step

You now know that the angle isn't just a number; it's the determining factor between a frustrating cut and a perfect one. Whether you choose 15° or 20°, the real key is consistency in that angle.

Now that we've mastered the geometry of the cutting edge, it's time to focus on the abrasive itself. The grit of the abrasive will determine the speed at which you recreate that perfect bevel and the ultra-fine finish of the edge.

➡️ Go to Article 3: The Heart of Sharpening: The Complete Guide to Grits and Abrasiveness.