Kai Double-Sided Sharpening Stone 400/1000 Grit 25 cm

€44,90

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📋 Description

Professional Kai whetstone – Dual grit 400/1000 with support 25 cm

The Kai dual-grit 400/1000 whetstone is the reference tool for professional blade maintenance in the kitchen. Made of high-quality ceramic and produced in Japan by a brand with over a century of history in professional cutting, it offers on a single stone (25.2 × 9.4 × 5.0 cm) the abrasive grit for restoring damaged blades and that for daily maintenance. The included non-slip support ensures stability during sharpening and serves as a water immersion tray.

Grit 400 and grit 1000: two surfaces, one professional tool

The 400 grit is the coarse abrasive surface, designed to resharpen significantly worn or micro-chipped blades. It removes material efficiently, restoring the original edge profile in reduced times. It is the starting point for knives that have not received regular maintenance or have suffered mechanical damage.

The 1000 grit is the medium-grit surface, intended for daily blade maintenance: refines the edge, removes residual burrs from 400 grit work and restores a clean, precise cut. For knives in daily intensive use subjected to regular maintenance, 1000 grit is sufficient for routine maintenance without moving to 400 grit.

Why a perfectly sharpened blade changes kitchen work

In the foodservice industry and professional pastry, cut quality is not a detail: it impacts the precision of mise en place, plate presentation and operational safety. A correctly sharpened blade requires less force, reduces the risk of accidental slips and preserves ingredient structure. Whether Kai, Zwilling, Wüsthof, Global or any other professional knife, the Kai 400/1000 whetstone is compatible with both double-sided honed blades (European type) and single-sided blades (Japanese tradition).

Technical features of the Kai 400/1000 whetstone

Available grits: 400 (resharpening) / 1000 (maintenance)
Material: High-quality ceramic
Dimensions: 25.2 × 9.4 × 5.0 cm (L × W × H)
Included support: Non-slip tray with dual function (stabilisation and immersion)
Blade compatibility: Double-edged blades (European) and single-edged blades (Japanese)
Recommended sharpening angle: 15° for Western blades; for traditional Japanese blades, respect the original angle
Usage method: Water-based (soak 10 minutes before use)
Origin: Made in Japan

Professional sharpening instructions

Before using the whetstone, soak it completely in water for about 10 minutes. During sharpening, always maintain a light film of water on the surface: it ensures optimal blade cooling and consistent ceramic performance.

I. Double-sided honed blades (double-edged – European type)

a. Position the whetstone lengthwise in front of you on the work surface. Hold the knife with the edge facing you at 45° to the whetstone and tilt it at 15° to the surface.

Knife positioning on Kai whetstone for double-edged blades – 15° angle

b. Start from the tip of the blade. Apply light pressure with your fingertips on the edge, eliminating any gap between whetstone and blade.

c. Push the knife away from you with light pressure, then return it towards you without pressure. Gradually shift your fingers towards the handle to cover the entire edge length. Repeat the cycle for at least five passes.

d. Turn the knife and repeat the process with the same number of passes on the other side.

e. Rinse the knife and whetstone thoroughly with clean water.

II. Single-edged blades (Japanese tradition)

a. Position the whetstone lengthwise in front of you. Hold the knife with the edge facing you at 45° to the whetstone, resting the sharpened side in the lower part of the abrasive surface.

Positioning of Japanese single-edged knife on Kai whetstone

b. Start from the tip of the blade. Apply light pressure with your fingertips on the edge. The sharpening angle derives from the blade's original sharpening and should not be modified.

c. Push the knife away with light pressure, then return it towards you without pressure, moving your fingers towards the handle. Continue until you feel a burr forming* on the opposite side. At least five passes are necessary.

Burr formation during sharpening of a single-edged Japanese blade

d. Turn the knife and rest the concave side of the blade flat on the whetstone. Push with light pressure until the burr is no longer felt. Alternatively, remove the burr with a nylon brush or newspaper.

Burr removal on the concave side of the Japanese blade

e. Rinse the knife and whetstone thoroughly with clean water.

* A burr is a very thin layer of metal that forms during sharpening on the side opposite the whetstone.

Kai: over a century of Japanese excellence in blade production

Founded in 1908, Kai is the leading Japanese brand for the production of professional knives, scissors and sharpening tools. Kai whetstones are chosen by Michelin-starred chefs, top pastry laboratories and hospitality professionals who accept no compromises on cut quality. Choosing the Kai 400/1000 whetstone means investing in a blade maintenance system designed to last with consistent performance.

Frequently asked questions

What is the difference between the 400 and 1000 grit of the Kai whetstone?

The 400 grit is coarse abrasive: it serves to resharpen very worn or micro-chipped blades, removing material efficiently to restore the edge profile. The 1000 grit is medium-grit and is dedicated to daily maintenance: it refines the edge, removes residual burrs and restores a sharp, precise cut. For regularly used and well-maintained knives, 1000 grit is sufficient for routine maintenance.

Which knives is the Kai 400/1000 whetstone compatible with?

The Kai 400/1000 whetstone is compatible with double-sided honed blades (European type, such as Zwilling, Wüsthof, Global) and single-edged Japanese tradition blades. The recommended sharpening angle is 15° for Western knives; for Japanese blades, it is recommended to respect the original sharpening angle.

How is the Kai whetstone prepared before use?

Before each sharpening session, soak the whetstone completely in water for about 10 minutes. During use, always maintain a light film of water on the surface: it ensures optimal blade cooling and consistent ceramic performance.

How often is it necessary to sharpen professional knives with the Kai 400/1000 whetstone?

The frequency depends on intensity of use and blade type. In a professional kitchen with daily intensive use, maintenance with 1000 grit is recommended every 1-2 weeks. The 400 grit is used only when the blade shows significant wear or micro-chips that routine maintenance cannot correct.

What is the support included with the Kai whetstone for?

The included support serves a dual function: it stabilises the whetstone on the work surface during sharpening thanks to a non-slip base, preventing accidental slipping, and it serves as a tray for soaking the whetstone in water before use. The whetstone dimensions are 25.2 × 9.4 × 5.0 cm.