Naniwa Chosera #400

When regular sharpening is no longer enough.

A knife that has become thick behind the edge, developed small chips, or lost its original geometry often needs more than a fine sharpening stone. Before refining the edge, the shape itself must first be corrected.

The Naniwa Chosera #400 is a coarse sharpening stone designed for exactly this kind of work.

Its strong cutting ability allows steel to be removed efficiently, making it particularly useful for edge repair, thinning, geometry correction, and establishing a new bevel. Instead of spending unnecessary time trying to make major corrections with a medium-grit stone, the #400 lets you address the underlying problem first — then move efficiently into the finer stages of sharpening.

Why #400 Matters

A finer stone can improve an edge, but it cannot efficiently correct every problem.

If a knife has become too thick behind the edge, has an uneven bevel, or requires significant material removal, continuing to sharpen only with medium or fine stones can consume time while leaving the fundamental geometry unchanged.

The Chosera #400 gives you the cutting power needed to correct first, refine second.

It is particularly useful for:

• Repairing small chips and damaged edges
• Thinning behind the edge
• Correcting uneven or distorted bevels
• Establishing or rebuilding bevel geometry
• Preparing the blade for progression to medium and finishing stones
• Professional knife maintenance and restoration

A Foundation Stone for Serious Sharpening

A truly sharp knife is not created by the finishing stone alone.

The quality of the final edge depends heavily on the work completed in the earlier stages. When substantial correction is required, the #400 provides the foundation upon which the rest of the sharpening process is built.

For sharpeners who maintain knives over many years — rather than simply touching up an edge — a reliable coarse stone is an essential part of the sharpening system.

Correct the geometry. Restore the foundation. Then refine the edge.