How to Choose the Right Whetstone Grit for Your Japanese Knives
Maintaining Japanese knives properly starts with understanding your whetstone grit. Using the right sharpening stones ensures your blades stay sharp, precise, and long-lasting. In this guide, we’ll break down how to select whetstone grits, when to use them, and how polishing stones, along with Atoma Diamond Plates, help keep your stones performing perfectly.
What Is Whetstone Grit?
A whetstone’s grit measures the size of the abrasive particles in the stone.
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Lower numbers = coarser particles = faster metal removal
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Higher numbers = finer particles = slower metal removal, smoother edges
Think of it like sanding wood: coarse paper reshapes quickly, fine paper polishes. The same principle applies to knives.
Why Flattening Whetstones Matters
Over time, whetstones wear unevenly, forming dips that prevent consistent sharpening. Using an uneven stone can ruin your edge.
Atoma Diamond Plates are essential for keeping your stones perfectly flat. They:
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Remove high spots quickly and efficiently
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Ensure even contact across the blade edge
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Extend the life of your whetstones
Regular flattening with a diamond plate keeps your sharpening consistent, whether you’re using coarse, medium, or fine stones.
Understanding Whetstone Grit Ranges
Most kitchen sharpening stones fall into three main categories: coarse, medium, and fine. Each has a specific purpose for Japanese knives and other high-quality blades.
Coarse Stones (<400 Grit)
Purpose: Repairing damaged edges and establishing a new bevel.
Use coarse stones if:
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Your knife has chips or nicks
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The edge is dull or rounded
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You need to reset the blade angle or thin thick edges
Notes:
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Coarse stones remove metal quickly but leave visible scratches.
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Always follow with finer stones to refine the edge.
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Use an Atoma Diamond Plate occasionally to flatten your coarse stone for optimal performance.
At Blade & Board, we recommend starting with a <400 grit stone only for serious edge repair.
Medium Stones (800–2000 Grit)
Purpose: Regular sharpening and edge maintenance.
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1000 grit: Ideal for most Japanese carbon and stainless knives. Restores dull edges efficiently.
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1500–2000 grit: Smooths scratch patterns and improves cutting performance.
This range is the “workhorse” of your knife care. Most home cooks and professional chefs do the majority of their sharpening here.
Flatten your medium stones regularly with a diamond plate to maintain a perfectly flat surface.
Fine & Polishing Stones (3000–8000 Grit)
Purpose: Refining and polishing edges for precision cutting.
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3000–4000 grit: Perfect for sashimi, delicate vegetables, and precision slicing.
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6000–8000 grit: Creates mirror-like edges and ultra-smooth cuts. Ideal for polishing knives.
Polishing stones don’t just look impressive — they reduce friction, improve slicing performance, and maintain sharper edges longer. Flatten these stones occasionally with an Atoma Diamond Plate to ensure consistent results.
Recommended Whetstone Grit Combinations
| Skill Level | Stones | Purpose |
|---|---|---|
| Beginner/Home Cook | 1000 grit + 3000 grit | Regular sharpening and basic polish |
| Enthusiast | <400 grit, 1000 grit, 4000 grit | Repair, maintenance, and edge refinement |
| Professional / Perfectionist | <400 grit, 1000 grit, 4000 grit, 6000–8000 grit | Full progression from repair to polishing |
Use Atoma Diamond Plates to flatten your stones periodically. This keeps all grit levels effective and prevents uneven edges.
Matching Grits to Knife Types
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Japanese Carbon Steel: Responds well to finer grits. 1000 + 3000/4000 grit is ideal.
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Japanese Stainless (VG10, Ginsan): 1000 grit for sharpening, 3000–4000 grit for refinement.
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Western Stainless: 1000–2000 grit usually sufficient; higher polishing grits provide little real benefit.
Learn More About Japanese Knives
Key Takeaways
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Use coarse stones (<400 grit) only for repair or reshaping.
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Medium stones (800–2000 grit) are your everyday sharpening workhorse.
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Fine and polishing stones (3000–8000 grit) refine the edge and improve slicing performance.
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Flatten your stones with an Atoma Diamond Plate to maintain even surfaces and consistent results.
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Technique matters more than grit number.
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Progressive sharpening works best. Start coarse if needed, refine with medium stones, then polish for precision.
Sharpening is both a science and an art. Using the right stones, flattening them properly, and polishing your edges will keep your knives performing at their best and extend their lifespan.