Your sharpening stone wears down over time – and a concave surface falsifies the sharpening angle with each pass. This kit of two flattening stones (180 and 320 grit) restores your waterstones to perfect flatness, extends their lifespan, and ensures a constant and precise sharpening angle. Compatible with all traditional waterstones, diamond stones, and rotary sharpener discs.
Why flatten your sharpening stone?A new sharpening stone is perfectly flat. After a few months of use, the center becomes hollow — where the blade passes most often. This concavity, even slight, has direct consequences on the quality of sharpening: the angle varies from one pass to another, the edge is uneven, and the results gradually deteriorate without understanding why. The flattening stone is the tool that corrects this problem in a few minutes.
A flat surface = a constant angle with each pass. This is the essential condition for obtaining a symmetrical and durable edge, regardless of your skill level.
A regularly flattened stone lasts years longer than a neglected one. A few minutes of investment that saves you from buying a new one.
The grooved surface of the 180 grit stone collects abraded stone residue and prevents the surface from clogging during rectification.
Traditional waterstones, diamond stones, and discs of modern rotary sharpeners: one kit for all sharpening equipment.
Two complementary grits to cover all levels of wear, from emergency repair to routine maintenance.
- For heavily dished or deformed stones after long use.
- Deep grooved surface that effectively removes residue during rectification without clogging.
- Quickly removes material to restore flatness in minutes.
- Use first on heavily worn stones.
- For regular maintenance of waterstones that are still in good condition but slightly concave.
- Especially suitable for the stone discs of rotary sharpeners — gentler for these more delicate surfaces.
- Flattening finish after 180 grit for a perfectly smooth and uniform surface.
- Cleans and refreshes the abrasive surface of rotary discs.
- Heavily dished stone (concavity visible to the naked eye): 180 grit, then 320 grit finish.
- Slightly concave stone (concavity by touch or with a ruler): 320 grit alone is sufficient.
- Rotary sharpener discs: 320 grit only — gentle, for cleaning and refreshing.
- Preventive maintenance (after each series of sharpenings): 320 grit, 1 to 2 minutes.
The technique is simple and requires no additional equipment — just water and a few minutes of circular work.
Immerse the flattening stone(s) in cold water for 2 to 5 minutes before use. Water lubricates the surface, facilitates the work, and prevents residue from embedding.
Heavily dished stone → start with 180 grit (black stone). Slightly concave stone or rotary disc → 320 grit (white stone) directly. Add water to the sharpening stone throughout the operation.
Place the flattening stone flat on the sharpening stone. Rub in circular or figure-eight motions, covering the entire surface — focus on the most concave areas. An abrasive slurry will form: this is normal, do not rinse it during work.
Check regularly with a metal ruler. When no light passes through, the surface is flat. Rinse the sharpening stone with clear water to remove the slurry and let it air dry before storing.
Do not neglect regular flattening — it is the most important and most often overlooked maintenance. A stone flattened after each series of sharpenings (10 to 15 sessions) never truly becomes concave, and the rectification work then only takes 2 minutes. However, a stone left concave for months may require 15 to 20 minutes of 180 grit to be recovered.
During rectification, the abrasive slurry that forms is useful — it is composed of particles from your sharpening stone and aids in leveling. Do not rinse it during work. Rinse only at the end, once flatness is achieved.
| Specification | Details |
|---|---|
| Type | Flattening Stone Kit — Sharpening Stone Fixer |
| Grits included | 180# (coarse, grooved black stone) + 320# (fine, small white stone) |
| 180 Grit Surface | Grooved — optimal residue evacuation |
| Lubricant | Water only |
| Compatibility | Traditional waterstones, diamond stones, rotary sharpener discs |
| Usage | Heavy repair (180#) + routine maintenance and finishing (320#) |
Essential for anyone who regularly sharpens with stones. Without flattening, results gradually and imperceptibly deteriorate.
The 320 white stone is specially adapted for the discs of rotary systems — cleans, refreshes, and keeps abrasive discs in perfect condition.
For those who master their sharpening angle and do not want the condition of their stone to undermine this precision work.
The ideal complementary accessory to offer with a sharpening stone or rotary sharpener — often forgotten, always essential.
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