Choosing a sharpening stone: grit, water or oil

A butcher's steel does not do what a stone does. It realigns an edge bent by use, without removing any steel: that is honing. A stone, by contrast, removes material to reform an edge once it no longer realigns: that is sharpening. This distinction, and the motion of the steel itself, are covered in « How to sharpen a knife: a cutler's method »; they are not repeated here.

A diamond steel abrades instead of realigning: with every pass it wears away a little of the blade, exactly what everyday care is meant to avoid. The workshop therefore recommends a medium-cut steel, which realigns the edge without wearing it down, the only kind suited to a gesture repeated without a second thought.

What actually leads to the stone is an impact on the edge, a use the blade was not made for, or long neglect, never everyday use. A Résiliant leaves the workshop razor sharp, and cared for with a steel, it stays that way for a long time without a stone being necessary. The stone then becomes the exception, not the routine: what it takes once it truly is needed is the subject of the rest of this article.

Grit is the number attached to every sharpening stone sold commercially. It reflects the density of the abrasive particles bonded or aggregated within the stone: the higher it is, the finer and more numerous the particles, and the smoother the surface left on the steel.

A low grit cuts fast but leaves deep scratches; a high grit removes almost no material but polishes the edge to a mirror finish. Between the two, no grit is "better" than another: each answers a different state of the blade, from a badly damaged edge to simple finishing maintenance.

Japanese sharpening tradition sorts stones into three grades that follow this same logic: ara-to for shaping very worn or chipped blades, naka-to for routine sharpening, and shiage-to for finishing, the stage that gives the edge its final polish. This three-tier hierarchy, born in Japan, has spread well beyond its stones of origin and now structures most ranges sold today, Japanese or not.

Choosing a grit therefore comes down to a single question: what state is the edge in? A blade that is merely dull only needs a medium to fine grit; a chipped or badly worn blade first needs a low grit, before moving progressively toward the fine end. That progression is the subject of the next section.

A complete sharpening progression rests on three grit stages, each with its own role: shaping a chipped or badly worn blade, sharpening an edge that needs reforming, then finishing and polishing that edge so it cuts cleanly. Jumping straight from a coarse stone to a finished edge without an intermediate step leaves marks a fine stone alone cannot undo.

In practice, few knives need all three stages at once. A coarse stone is only needed on a damaged, chipped or long-neglected blade: that is the exception, not the routine. For the vast majority of sharpening sessions, a single medium-grit stone, or a combination medium/fine stone, covers the needs of a pocket or kitchen knife. Le Résiliant 2.0, in carbon steel with a finer grind than the Tanto, illustrates the point well: its blade, known for being easy to sharpen, comes back sharp with that single medium stage.

The motion that follows, once the stone is chosen, angle held, regular strokes, forming then removing the burr, is not the subject of this article: it is covered step by step in « How to sharpen a knife: a cutler's method ».

A combination stone, with two grits on its two faces, remains the most economical option for anyone owning a single accessory: it covers light shaping on one side and finishing on the other, without multiplying purchases.

The liquid applied to a stone is not a matter of comfort: it has a precise mechanical role, keeping afloat the slurry of abrasive particles and metal torn from the blade. Without that film of liquid, the slurry clogs the stone's pores and the abrasive stops biting efficiently.

At equal grit, water is the more aggressive liquid: low in viscosity, it flows fast, clears the slurry continuously and keeps the abrasive in direct contact with the steel. That is why a water stone seems to "cut" faster than an oil stone of the same grit: the abrasive itself has not changed, only how exposed it stays.

Oil, being more viscous, slows that movement: it traps part of the slurry at the surface instead of clearing it, which wears the stone more slowly but makes each stroke a little less biting. Not every oil suits the task, though: mineral or vegetable oils that are too viscous or drying, which harden as they dry, end up gumming the stone's surface instead of cleaning it.

Neither liquid is a recent invention: Pliny the Elder was already describing the use of water and oil for sharpening in Roman Antiquity. The choice between the two is therefore not a matter of fashion, but a trade-off between speed of abrasion and ease of upkeep, to be made according to the stone chosen rather than personal taste.

Natural stones are cut from rock whose abrasive is an integral part of it: it is the mineral structure itself that wears the steel down. The best documented is Arkansas novaculite, a siliceous rock whose quartz crystals measure 3 to 5 microns, roughly equivalent to an American grit of 600 to 1200. That natural fineness confines it to finishing stages, not shaping.

A natural stone also carries an irregularity synthetic stones do not know: the density and size of the crystals vary slightly from block to block, even within the same quarry, which gives every stone its own behaviour, slower to master but often prized for the quality of the polish it leaves.

The arrival of synthetic abrasives, corundum in particular, changed the picture: their grit is calibrated industrially, so it stays constant from stone to stone, and their biting power is higher at equal grit. That consistency and aggressiveness make them the tool of choice for modern steels, harder and more heavily loaded with carbides than traditional ones.

The choice between the two is therefore not tradition versus modernity, but a matter of use: a fine natural stone works well on a softer steel already close to sharp, a synthetic stone gets there faster on a hard steel that resists abrasion.

Not every steel abrades the same way. Its hardness and its carbide content, those very hard particles scattered through the steel's matrix, resist the abrasive to very different degrees from one grade to the next: the more numerous and harder the carbides, the harder and more aggressive the abrasive must be to cut into them.

That is the case with D2, also designated Z160 in Europe, two names for the same steel: an ordinary stone, corundum or novaculite, takes longer to get through it than through a simpler steel, and wears out faster itself in the process. Two models in the collection are directly concerned: Le Résiliant Tanto and Le Mancharicou, both built in D2 steel.

Faced with this kind of steel, two abrasives take over from ordinary stones. Diamond, the hardest material known, barely dulls on contact with carbides: a diamond stone or plate keeps its cutting power far longer than an ordinary stone on these steels. Very hard ceramic plays a similar role, mostly for finishing, polishing an edge without heating it.

Le Shotokan, offered depending on the version in carbon steel, semi-stainless Z160 or damascus, illustrates this diversity well: each version calls for an abrasive suited to its own hardness, without any version being harder to maintain day to day. This is never a matter of comparing steel families against each other: every grade, whatever its family, calls for an abrasive proportioned to its hardness and its carbide load.

A sharpening stone does not wear evenly: the centre, used the most, hollows out faster than the edges. That dip, invisible at first, then throws off the angle of every stroke without you noticing, making results more and more uneven from one session to the next. A stone that is never flattened ends up imposing its own curve on the blade instead of the other way round.

Flattening means rubbing the stone flat against a dedicated abrasive surface, often a coarser stone or a purpose-made plate, until a perfectly flat surface returns. How often depends on use: the more a stone works, the more it hollows, the more it needs flattening.

Next comes routine care, which differs by stone type. A water stone soaks before use, until air bubbles stop rising to the surface, then rinses during sharpening. An oil stone is never soaked: a few drops before each session are enough, and a careful wipe afterward keeps it from clogging. Either way, the stone must dry fully before being put away, out of reach of lingering damp.

Sharpening on a stone is a skill of its own, learned with practice: holding a constant angle, judging each stroke, recognising the burr. A repeated mistake can bend the edge to the point where the whole grind and polish need reforming. On a blade worth keeping, the attempt then costs more than the service: neither drama nor fatalism, just a motion that takes practice before being tried alone.

That is why the workshop recommends, once an edge is truly gone, entrusting it to a cutler rather than risking it alone. Any knife that has left the workshop can be sent back for its edge to be restored, free of charge: only return shipping is down to its owner. A message to the workshop before any shipment. The site's contact page is the starting point for arranging the return. The accessories page notes, for that matter, that sharpening stones will one day join the range; they are not there yet today.