Whetstone Grits Explained: 400, 1000, 3000 & 6000

Whetstone grit is a measure of abrasive particle size: the higher the number, the finer the particles and the smaller the scratches they leave. Low grits (200–600) remove metal fast and repair damage. Mid grits (800–2000) create the actual cutting edge. High grits (3000+) refine and polish an edge that already exists. For a home kitchen, a 1000-grit stone does the real work and a coarse or fine partner covers the extremes.

The confusion is that grit numbers are not a universal standard. A Japanese 1000 is not the same particle size as an American 1000, and diamond plates use a different scale again — which is why a 325-grit diamond plate behaves more like a 600-grit waterstone. Do not compare numbers across systems. Compare what the stone is for. That is what the chart below does.

Grit	What it is for	When to reach for it
120–400	Repair: reprofiling, removing chips, resetting a bevel	A chipped knife, or a first sharpening of something badly neglected
800–1200	Sharpening: raises the burr and forms the working edge	Every sharpening session — this is the essential grit
2000–3000	Refining: removes the coarse scratch pattern, tidies the apex	When you want a cleaner cut on soft produce and tomatoes
5000–8000	Polishing: a bright, smooth, low-friction edge	Japanese knives, straight razors, and people who enjoy this
10000+	Mirror finishing	Razors and display edges — not kitchen knives

If you buy one grit, buy 1000

A 1000-grit stone is where an edge is actually created. Everything below it exists to save you time when there is a lot of metal to remove; everything above it exists to make an edge that already exists smoother. A knife sharpened only to 1000 grit is properly sharp — it will glide through a tomato and shave paper — it just has a slightly toothy edge rather than a polished one. For most home cooking, toothy is not a disadvantage. It bites into skin and crust better than a polished edge does. This is why our whetstone roundup is built around 1000-grit stones and 1000/6000 combinations rather than exotic progressions.

When you genuinely need a coarse stone

Reach below 600 grit only when there is real damage: a visible chip, a rolled section, a tip that snapped, or a knife so dull that ten minutes on 1000 grit has not raised a burr. Coarse grits eat steel, and steel does not grow back — a habit of starting every session at 220 will visibly shorten the life of a knife over a decade. The one clear exception is a beginner's first session on a neglected knife, which is exactly why our beginner stone list leads with a 400/1000 combination.

When a high grit is worth it

Above 3000 you are polishing, and polishing pays off in two situations. The first is hard Japanese steel: a fine-grained alloy at 60–63 HRC can hold a polished apex that softer German steel simply cannot, so the refinement survives long enough to be worth the effort. The second is pure enjoyment, which is a perfectly good reason. What a high grit does not do is make a knife last longer between sharpenings — edge retention comes from the steel and the hardness, which we cover in the knife steel guide, not from the finish.

The progression, in practice

A normal session is short. Start at the coarsest grit the damage actually requires, work one side until you can feel a burr along the full length of the edge, do the same on the other side, then move up. On each finer grit you are removing the scratches left by the previous one, so you need far fewer strokes than you think — the fine stones are not where the metal comes off. Finish by cutting the burr away with a few very light alternating passes. The full motion, including how to feel for the burr, is in our step-by-step guide.

Diamond, ceramic and waterstone grits are not comparable

Three different scales are in common use, and manufacturers do not translate between them. As a rough working guide, a coarse diamond plate around 325 removes metal at roughly the rate of a 600-grit waterstone, and a fine diamond plate around 1200 finishes somewhere near a 2000-grit waterstone — while feeling completely different under the blade. Ceramic stones sit closer to the Japanese waterstone scale but cut harder. The practical advice: buy by intent, not by number. A stone marketed as a coarse repair stone, a sharpening stone, or a finishing stone is telling you more than its grit does.

Grit and your knives

Soft German steel around 56–58 HRC does not hold a polished edge for long, so stopping at 1000 or 2000 grit and honing regularly is the efficient routine — see how to use a honing steel. Hard Japanese steel rewards going further, and the difference is genuinely noticeable on delicate work. If you are still choosing between the two philosophies, the Japanese vs German comparison is the place to start, and the angle guide covers the other half of the decision.

How we picked

We did not lab-test these knives

Everyone in this category says they tested twenty knives in a professional kitchen. We have not hands-on tested any of these, and we say so. What we did instead: compiled the published specifications — steel type and hardness (HRC), edge angle, blade geometry, weight and build — applied established sharpening standards, ran the value math (spec quality ÷ live price), and scored each product against a published rubric. The scores are judgments from documented research — not measurements we took, because we do not have a test lab and we will not pretend we do. Where a number came from someone else's work, we name them in Sources.

Questions

Frequently asked

What grit whetstone is best for kitchen knives?

1000 grit. It creates the working edge, and a knife sharpened only to 1000 is genuinely sharp. Add a coarse side if your knives are badly dull, or a 3000–6000 side if you own hard Japanese steel and enjoy refining.

Do I need a 6000-grit stone?

Only if you want a polished edge for its own sake or you own hard Japanese steel that will hold one. For German steel, honing regularly does more for everyday sharpness than a finishing stone does.

Is a higher grit sharper?

Smoother, not necessarily sharper in use. A 1000-grit edge is slightly toothy and often bites better on tomato skin and bread crust. A polished edge glides more cleanly through soft protein.

Why do diamond plates use different grit numbers?

Diamond, ceramic and Japanese waterstones use separate grading scales, so the numbers do not translate. A 325-grit diamond plate cuts roughly like a 600-grit waterstone. Buy by what the stone is for, not by the number on it.

Can I skip grits in a progression?

Yes, within reason. Jumping from 400 straight to 6000 means the fine stone has to erase deep scratches and will take a long time. Doubling the grit each step is a reasonable rule; most kitchens only need two stones anyway.

Keep reading

Receipts

Sources

We do not run a testing lab, and we do not pretend to. Where a spec or a measured number came from someone else's work — a manufacturer's page, a published standard — we name them and link them. Where we could not verify something, we say so on the page rather than quietly leaving it out. Read our full method.