Shapton GlassStone 4000 Grit Ceramic Whetstone – 3 Micron Type WA

The Shapton GlassStone 4000 is a fine finishing waterstone for smoothing the scratch pattern after medium-grit sharpening and creating a controlled, polished kitchen edge. Its 3-micron-class Type WA layer cuts cleanly without requiring a soak.

This is the full-size Shapton GlassStone GS/HR model—not GlassStone Seven, RockStar, or the HC formulation. Type WA identifies Shapton’s white-alumina abrasive. A 5 mm sharpening layer is permanently laminated to 5 mm tempered glass for a precise, stable working surface.

Why choose the 4000 grit

Finishes edges after 1000- to 2000-grit sharpening

Refines burrs and medium-stone scratch patterns

Creates a smooth edge that remains practical for kitchen work

Specifications

Brand: Shapton

Series: GlassStone / GS Series HR

Manufacturer SKU: 50103

Barcode: 4944509501032 (GTIN-13 / JAN)

Grit: 4000

Particle class: 3 micron class

Abrasive type: Type WA (white alumina)

Construction: 5 mm abrasive layer laminated to a 5 mm tempered-glass base

Dimensions: 210 × 70 × 10 mm (8.27 × 2.76 × 0.39 in.)

Product weight: Approximately 360 g (12.7 oz.)

Water preparation: Splash-and-go; no soak required

Included: One GlassStone; holder sold separately

Country of origin: Japan

How to use

Secure the stone on a non-slip stone holder with the abrasive face up.

Add clean water and begin sharpening. An optional 5–6 minute wetting can improve feel, but long soaking is unnecessary.

Maintain a consistent angle and use controlled pressure, adding water as needed.

Flatten periodically with a compatible lapping plate to preserve accuracy.

Care

Rinse after use and let the stone dry completely at room temperature before storage. Do not use detergent, hot water, direct sun, forced heat, or long-term soaking. Keep the sharpening face flat and free of embedded coarse grit.

Build a Shapton progression

Use after the GlassStone 2000. Finish here for a polished working edge, or continue to the GlassStone 8000 for a more highly polished finish. Browse the full Shapton whetstone collection.

Common questions

Does a GlassStone need soaking?

No. It is designed for splash-and-go use. A brief optional wetting can improve feel; avoid long soaking.

What does Type WA mean?

WA is Shapton’s designation for white alumina, the abrasive used in this model.

Is this a RockStar or GlassStone Seven?

No. This is the full-size, 210 × 70 mm GlassStone with a 5 mm abrasive layer on a 5 mm tempered-glass base.