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Buying Guide
Choosing the Right Sharpening Stone
The performance of a sharpening stone is determined by two key traits: durability (how long it lasts) and aggression (how fast it cuts). This guide explains the different aspects of each stone type and can be used to decide which stones are best for your individual needs.
The Core Trade-Off
Cuts SlowerCuts Faster
Wears FasterLasts Longer
Start Here
Quick Recommendation
Simplest Setup
A ceramic waterstone: no soaking required, minimal flattening needed.
See ceramic waterstones →Facilities That Must Stay Clean
Oil stones cut without producing a slurry so they're the best choice for fishing boats, processors and restaurants that need a super clean setup.
See oil stones →Most Versatile
Traditional waterstones provide excellent cutting aggression and the largest variety of grit sizes.
See waterstones →High Rockwell Steel
Naniwa diamond stones are our top choice for ultra-hard knives. These stones are built to cut quickly and hold their shape with any blade.
See diamond stones →Where to Start
The Two Families of Stones
Natural Stones
Rocks hewn from the earth in their natural form, then cut and shaped to a size suitable for sharpening. A handful of famous deposits around the world each have their own crystalline structure and characteristics; in the US, Arkansas (novaculite) stones are the most prevalent.
Man-Made Stones
An abrasive (silicon carbide, aluminum oxide, industrial diamond, or ceramic) is bonded into a medium designed either to hold it firmly in place, or to slowly wear and release fresh abrasive underneath.
Before You Shop
Why Buying Stones Is Harder Than It Should Be
Most manufacturers won't tell you what actually matters. When we're vetting a new stone to carry, we ask for the bonding agent and the aggregate quantity, and the answer is usually "proprietary." Even naming the abrasive doesn't tell you much: there are roughly seven different types of aluminum oxide alone, including a vitrified aluminum oxide that's been superheated into glass and reformed into a stone. Without that information, most of what's out there ("I like this brand," "I like that one") is anecdotal, not evidence.
That's why we don't add a new stone to the lineup quickly. New products go through five to six months of real testing on our own bench before we're willing to recommend them, checking whether they cut consistently all the way through the stone, not just out of the box.
Country and consistency of manufacture matter more than people expect, too. A lot of traditional waterstones are made in China under a rotating cast of brand names, and we've seen real batch-to-batch inconsistency in them; we test incoming shipments and have rejected batches that wore too fast or wouldn't reliably generate a slurry. Stones sourced from Japan have been far more consistent for us. Natural stones make this worse, not better: a Belgian Blue or a Japanese natural stone's properties depend entirely on the specific deposit and sediment they came from, so there's no substitute for testing a given source firsthand.
Trying a few stones firsthand is really the best way to find the right one, but that isn't always practical before you buy. In our experience, quality varies more in the bonding agent than in the abrasive itself; that's where most of the real differences between brands and stone types show up, and it's what we lean on most when helping customers pick a stone. The breakdowns below reflect that hands-on testing, type by type.
Type 01 · Natural
Arkansas Stones
The most common natural stone in the US market, graded by color and texture. From coarsest to finest: Soft Ark, Hard Ark, Black Ark, Translucent. The name "surgical black" isn't marketing: that grade really was used for surgical tools historically, since it's extremely smooth and fine.
Our honest take: the finest grades (Black and Translucent) will polish beautifully, but in our experience they don't cut fast enough to be practical for most sharpening work; they're better thought of as a specialty polishing stone than a stone you'd sharpen on regularly. What they're genuinely excellent at is not dishing, since they're solid quarried rock rather than a bonded aggregate, and they hold their flatness essentially forever. In our own shop, the main job we actually reach for one to handle these days is cleaning up the burr left on the back of a knife after flattening it with a diamond plate, rather than full sharpening.
Japanese natural stones, and European ones like Belgian Blues, are a separate category worth knowing about, though distinct from Arkansas stones: they're softer, create their own slurry as you use them, and are prized for polishing rather than speed. Each deposit has its own properties depending on the sediment it came from, so there's no substitute for testing a specific source firsthand, which is part of why they tend to be expensive.
Pros
- Extremely slow to wear, essentially never dishes
- High polishing capability
- Versatile: oil, water, or dry
Cons
- Slow cutting (low abrasion)
- Finest grades too slow-cutting for practical use
Cutting Speed
SlowFast
Wear Resistance
Wears quicklyVery slow to wear
Shop Natural Stones → · Knife Merchant Pick: RH Preyda 1000/6000 Combination Grit Arkansas Stone
Type 02 · Man-Made
Oil Stones
Oil stones are sometimes still called by their old name, carborundum stones. Norton Abrasives is the best-known maker. They come in two abrasive types: silicon carbide (fast-cutting, but fractures and wears faster) and aluminum oxide, sold as India stones (slower-cutting, but longer-lasting with a more polished result). Unlike waterstones, oil stones aren't sold by specific grit number; they're sold as coarse, medium, or fine, which is less precise but reflects how they're actually made and used.
In our experience, the largest demand for these stones comes from settings that need to stay clean and can't use a waterstone: fishing boats, poultry processors, and restaurant kitchens are the biggest markets for them. On fishing boats, it's common to see one just floating in the bait tank, often used completely dry with no oil or water at all, specifically to avoid creating any slurry mess; oil still gives better long-term performance, but dry works fine for a quick touch-up. Woodworkers reach for them too, especially for the initial coarse work on chisels, since they're less likely to gouge than some other stone types.
Pros
- Cleaner to use and store than a waterstone
- Very hard bonding agent: flat far longer than most stones
- Versatile: oil, water, or dry
- Good for chip repair
Cons
- Lower polishing ability
- Inconsistent, coarser cut than a specific-grit waterstone
- Clogging with metal fragments over time
- Eventual dishing under heavy daily commercial use
Cutting Speed
SlowFast
Wear Resistance
Wears quicklyVery slow to wear
Shop Oil Stones → · Knife Merchant Pick: Norton IM200 3-Stone Multi-Oilstone Sharpening System
Type 03 · Man-Made
Waterstones
The most common stone type for kitchen cutlery, split into two bonding styles. Traditional (Japanese) waterstones need to be soaked before use. Ceramic waterstones ("splash and go") need little to no soaking. The abrasive in both is almost always a form of aluminum oxide; the difference is the bond. Ceramic stones use a resin (phenol epoxy) or magnesia bond, which wears more slowly and cuts soak time down or out entirely. Traditional waterstones use a baked, soluble clay-and-feldspar bond, often blended with additional polishing agents.
Traditional Waterstones
Pros
- Excellent cutting aggression
- Large variety of grit sizes
- Good tactile feedback
- Less expensive than ceramic stones
Cons
- Soaking required
- Messy: lots of slurry
- Faster wear
- Regular flattening needed
Cutting Speed
SlowFast
Wear Resistance
Wears quicklyVery slow to wear
If you ask David directly, traditional waterstones are still his personal favorite of the four types: the cutting speed and control are worth the extra soak-and-mess overhead. Norton's 8000 grit is one he reaches for regularly in the shop and considers one of the best on the market at that grit. We've also spent months testing a newer US-made line, Pride Abrasives, whose 1000 grit in particular cuts noticeably more aggressively than a typical 1000, closer to what you'd expect from a 600, because of how much abrasive they pack into it.
Shop Traditional Waterstones → · Knife Merchant Pick: Norton Waterstone Starter Set (220/1000, 4000/8000, flattening stone, DVD)
Ceramic Waterstones
Pros
- Very slow wear rate
- No soaking required
- High to very high polish
- Minimal flattening needed
Cons
- Occasional need for a slurry (fixer) stone
- Lower cutting aggression
- More expensive
Cutting Speed
SlowFast
Wear Resistance
Wears quicklyVery slow to wear
What Most Sites Won't Tell You
A ceramic stone's labeled grit doesn't cut as aggressively as the same number on a traditional waterstone; ceramic stones simply carry less abrasive aggregate at a given grit size. If you're used to a 1000-grit traditional stone and want the same cutting speed in a ceramic, look at an 800-grit ceramic stone instead, and depending on the stone, sometimes even a 600. On stones 5000 grit and above, it also helps to raise a slurry first with a dedicated fixer (nagura) stone rather than spending your first 30 strokes just trying to get the stone cutting. A fixer stone runs about $8, though branded versions can cost several times that for the same thing. Match the fixer's grit to your stone's grit or lower, not higher, or you'll coarsen the surface you're trying to polish.
Naniwa and Shapton are the two major names in ceramic waterstones, and both make excellent quality; we carry Naniwa specifically, since there's no real reason to stock two categories of essentially the same tier. Naniwa itself splits into two lines worth knowing apart: the Super Stone, which carries less abrasive in a softer bond and is the more affordable entry point (and what we recommend as a first stone below), and the Professional line (formerly branded Chosera), which packs in more abrasive with a harder bond, lasts considerably longer, and is hard enough that you can use it almost like a diamond stone for chip repair, going straight into a chip without damaging the stone.
Shop Ceramic Waterstones → · Knife Merchant Pick: Naniwa 800 Grit Ceramic Super Stone
Type 04 · Man-Made
Diamond Stones
Most traditional diamond stones (the kind sold by brands like DMT) use industrial diamonds electroplated onto a steel plate. A newer generation, including Naniwa's Diamond Pro line, instead bonds a thin layer of diamond into a hard, vitrified base, so it handles and feels more like a splash-and-go waterstone than a plate. The two aren't interchangeable in feel or performance, and our experience with each is different.
On Traditional Plate-Style Diamond Stones
These are genuinely the best option for grinding out a chipped or damaged edge, or reshaping a heavy bolster on a forged knife by hand: you can go in perpendicular to the stone to fix real damage. But at finer grits, plate-style diamond can pull a little too much metal right at the very edge, which keeps it from leaving as clean a finished edge as a ceramic or traditional stone would. Part of the reason is structural: a diamond plate spreads its abrasive particles thinner than the same grit in a traditional stone's slurry, so the particles that do make contact tend to leave deeper scratches. We use plate-style diamond mainly for coarse and repair work and finish elsewhere. There's also a real quality gap between solid diamond plates and "interrupted" ones, which cover only about 40% of the surface with diamond (the rest is holes) to save on manufacturing cost; it's why we've stuck with solid Norton plates rather than the cheaper interrupted style.
On Naniwa's vitrified Diamond Pro line (the diamond stones we actually sell), our experience is different. The chart below is specific to Naniwa Diamond Stones, which use a vitrified (ceramic-glass) bond rather than a resin bond or a traditional electroplated plate, a distinction worth knowing if you're comparing diamond stones across brands, since bond type is the biggest factor in how a stone wears and feels.
Pros
- Splash and go with water
- Very little slurry, clean use
- Effective on high-Rockwell steel that other stones struggle with
- Long-lasting flatness (pair with a slurry/fixer stone)
- High polish
Cons
- Expensive
- 1000 and 3000 grits prone to loading up
KM Tip: The lower-grit Naniwa Diamond Stones can load up the included fixer stone quickly. We prefer using the Naniwa fixer stone instead.
Cutting Speed
SlowFast
Wear Resistance
Wears quicklyVery slow to wear
Shop Diamond Stones → · Knife Merchant Pick: Naniwa 1000 Grit Diamond Sharpening Stone
Side by Side
At a Glance
| Natural | Oil Stones | Traditional Water | Ceramic Water | Diamond | |
|---|---|---|---|---|---|
| Setup | Oil, water, or dry | Oil or water | Soak before use | Little to no soak | Splash and go |
| Cutting Speed | Slow | Moderate | Fast | Slow to moderate | Fast, even on hard steel |
| Wear Rate | Very slow | Very slow | Faster; needs flattening | Very slow | Very slow |
| Mess | Low | Low | High (lots of slurry) | Low | Very low |
| Best For | Slow, controlled polishing | Wash-down kitchens, chip repair | Fast progression through grits | Simple, low-maintenance setup | Very hard or high-carbide steel |
| Price | Moderate | Moderate | Lower | Higher | Highest |
Match to Your Knives
Choosing by Knife Type
For most Western-style, double-beveled knives, we recommend traditional waterstones. These soaking stones cut fast and offer a suitable level of polish. If you're looking for a mirror polish instead, ceramic stones are the better choice, since high-grit ceramics can create an unmatched shine.
Traditional hocho knives (single-beveled, urasuki chisel-ground) need an extremely flat stone, so we prefer ceramic sharpening stones for these blades. If budget isn't a factor, our preference is the Naniwa Diamond Stones. For a more moderate price point, there are still fantastic options. Shears also require an extremely flat stone, so the same recommendations here apply to anyone sharpening scissors and shears by hand.
Decision Time
Which Stone Should You Buy?
Recommendations by Use Case
Standard kitchen knives at home: a ceramic waterstone: no soaking required, minimal flattening needed, and high to very high polish.
A facility that must stay clean and can't use a waterstone: an oil stone: it's why fishing boats, poultry processors, and restaurants are the biggest market for them.
The widest grit selection and the most cutting aggression: traditional waterstones: the trade-off is soaking time and regular flattening.
High Rockwell steel: a diamond stone: built to cut steel types that give other stones trouble.
Technique
How to Use a Sharpening Stone
- 1Wet or oil the stone as its type requires: soak traditional waterstones, splash ceramic and diamond stones, apply a light coat of oil to oil stones.
- 2Hold a consistent angle, typically 15–20° per side for a kitchen knife. A steady angle matters more than the exact number.
- 3Grip the knife with two fingers near the edge and your thumb on the heel: that locks your wrist and keeps the angle steady, rather than fighting yourself by pushing from further up the spine.
- 4Work in sections rather than long sweeping strokes. Start at the tip, working that small section until you feel a burr form, then gradually slide your fingers down toward the heel as you move along the edge. Stay at a slight diagonal to the stone; squaring the blade up perpendicular to the stone will gouge it.
- 5Use both push and pull strokes, not just one direction; that's the more efficient way to raise a burr along the whole edge.
- 6Check for a burr (a thin curl of metal along the opposite edge) before switching sides. It tells you you've fully apexed that side.
- 7Switch hands and repeat the same motion on the other side, then move to progressively finer grits until the edge feels sharp and the burr is gone.
- 8Finish with a few light strokes from heel to tip, stopping before the tip slides off the edge of the stone, which can round it slightly.
- 9Strop or hone afterward if you want to remove any remaining microscopic burr and refine the edge further.
Maintenance
Keeping Your Stone Flat
Stones wear unevenly with use: the center, where most sharpening happens, wears faster than the edges, leaving the surface slightly dished. A dished stone makes it harder to sharpen accurately, since the blade no longer sits flat against it.
Traditional waterstones need this most often, given how quickly they wear; ceramic, oil, and diamond stones need it far less. Flatten with a dedicated flattening stone, like the Naniwa Pink Alumina Flattening Stone, by soaking both stones and working them together in a figure-8 motion (or simply alternating directions) under running water. A useful trick: draw a rough pencil grid across the stone's surface before you start; once every line is gone, you know the whole surface is flat. If you're not sure whether your stone needs it, lay a straightedge across the surface: any visible gap means it's time.
Perfect flatness matters more for some work than others. Specialty sharpening (shears, surgical tools) genuinely needs a dead-flat stone. For standard kitchen knife work, a slightly dished stone is still usable as long as it's even side-to-side in the direction you're actually sharpening; it doesn't need to be showroom-flat to do its job.
Common Questions
FAQ
What grit should I start with?
In most cases, a two-stone setup (something like 1,000 grit for setting or repairing an edge and 6,000 grit for polishing) is all you need. But every setup is a little different, and the right choice really depends on the stone type and the knives you're sharpening rather than one fixed number; what works for a soft home-kitchen steel isn't necessarily right for a hard powder-steel blade. If you're not sure, reach out; our team is happy to put together a personalized recommendation for your specific knives.
Do I need to buy an expensive stone holder?
No. A cheap non-slip shelf liner (the kind sold for kitchen drawers) under a scrap block of wood works just as well for most home setups, and costs about a dollar. If you do buy a dedicated holder, look for one with a low lip or clamp height, since that lets you use the stone all the way down to a small sliver before it's too short to hold safely, instead of retiring it early.
Can I use a waterstone dry, an oil stone with water, or an oil stone completely dry?
Waterstones need their lubricant; using one dry causes it to glaze over and stop cutting effectively. Oil stones are the flexible one: you can use oil, water, or nothing at all. Fishing boat deckhands commonly use theirs bone dry, specifically to avoid any slurry mess; it works fine for a quick touch-up, though oil gives the best long-term performance and cutting feel.
Should I rinse the slurry off my waterstone while sharpening?
No, leave it on. That gray paste isn't dirty metal filings, even though it can look that way; it's mostly the stone's own abrasive releasing as you work, and it's actively helping the stone cut. Rinsing it away constantly just slows you down and works against the stone.
What is a micro bevel, and should I use one?
A micro bevel is a second, slightly steeper edge added right at the very tip of the primary bevel; it makes the edge stronger and more chip-resistant. There's nothing wrong with adding one; how much depends on your knife and how you use it, anywhere from a couple of degrees to a fairly aggressive 25–30°. Keep it to your finest stone only, no thicker than a human hair; it's easy to grind back out the next time you sharpen.
Does my cutting board affect how often I need to sharpen?
More than people expect. Soft woods (maple, teak, Hinoki) are gentler on an edge than hard woods or nylon boards. Technique matters just as much: dragging food across the board while slicing rolls the edge over almost every time, while lifting the knife slightly and resetting between cuts preserves it. A good board and good cutting habits are the real first line of defense against a dull knife.
Should I strop after sharpening?
It's optional but helpful. A leather strop removes any remaining microscopic burr and can extend the time between full sharpening sessions.
How often do I need to flatten my stone?
It depends on the stone type and how often you sharpen. Traditional waterstones may need flattening every few sharpening sessions; ceramic, oil, and diamond stones need it far less often. When in doubt, check with a straightedge.
Mid-session, my stone doesn't seem to be cutting as well as it did at first. What's wrong?
It's probably "loaded": the surface has picked up enough metal that fresh abrasive isn't releasing properly anymore. Rinse the stone off and raise a fresh, clean slurry with a fixer (nagura) stone before continuing.
Do Naniwa's diamond stones ever wear out?
Eventually, yes, but far more slowly than any other stone type; that's the main reason they cost more. Because the diamond is bonded in a vitrified (ceramic-glass) base, fresh diamond is exposed as that layer gradually wears, similar to how a ceramic stone behaves. That's different from a traditional electroplated plate-style diamond stone (like a DMT), which carries a single fixed layer of diamond; once that layer wears through, the stone is done, since there's no more diamond underneath to expose.
