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How to sharpen a knife
by Sami P., 11.2.2022
Knife sharpening often comes with a bunch of questions—and maybe even a bit of mystery.
What is the correct angle for sharpening a knife? In what position is the knife held? When do I change sides? How hard do I press the knife?
Knife sharpening is a relatively straightforward process. By experimenting, you learn to find a good way of sharpening your knife to an excellent finish. Remember, there is no one right way in this craft either. And there’s no need to rush—staying calm always leads to better results.
In this blog, I won’t dive into whetstones, but instead I’ll answer some of the most frequently asked questions I’ve gotten over the years. Let’s start with the most common dilemmas that beginners tend to face.
WHAT IS THE CORRECT SHARPENING ANGLE FOR A KNIFE?
The sharpening angle is probably the most asked-about topic in knife sharpening. But truth be told, the angle often matters less than you think.
As a general rule of thumb, you can sharpen a good quality Japanese knife to 10–15 degrees, and honestly, no one will notice the difference between 10 and 15. That’s because quality knives are already thin by design, so small angle changes won’t be noticeable in use. On the flip side, if you sharpen a Fiskars knife to 10 degrees instead of 20+, the difference will be obvious. The softer steel won’t hold the edge, and it’ll feel dull after just a few tomato slices.
Some older articles still explain sharpening angles differently, but the common practice today is to refer to the sharpening angle rather than the total blade angle. For instance, if a Victorinox has an overall edge angle of 30 degrees, then the sharpening angle per side is 15 degrees.
So how much is 15 degrees? It’s about the same as lifting the spine of a chef’s knife 12 mm. That way, you've pretty much nailed the correct sharpening angle.
To summarize: Japanese knives usually fall in the 10–15 degree range. Western knives with HRC 58 hardness are best at around 15 degrees. Softer knives, like Fiskars or Sanelli, do better with a 20-degree angle.
WHAT IS A GOOD KNIFE SHARPENING POSITION?
Even beginners should find a sharpening setup that feels natural. The position doesn’t matter much—what’s important is that your shoulders stay relaxed and your hands move freely. I’ve sharpened sitting down, but I prefer standing at a bench that’s the right height.
I use a whetstone holder that raises the stone off the table. This gives your hands more room and makes it easier to rotate the stone, which is helpful when working on the opposite side of the knife.
You can move the knife along the stone either lengthwise or crosswise—direction doesn’t really affect sharpening performance. What matters more is that your stone is flat. The world is full of uneven whetstones, so make sure to flatten yours before getting started.
DO YOU NEED TO PUSH OR PULL THE KNIFE – AND HOW HARD?
There are lots of questions about sharpening technique, but some answers only come from experience. Trial and error is the name of the game.
A typical beginner mistake is being too careful. If your knife is dull, you need to make the most of your whetstone and apply the right amount of pressure.
A simple rule: the coarser the stone, the more pressure you can use. That means pressing the knife against the surface to get metal off efficiently.
People sometimes ask how many kilos of pressure to apply—but it’s not that exact. It depends on the knife, the steel, and the stone. Use the amount of pressure that feels natural. Too light, and sharpening takes much longer. With experience, you’ll develop a solid feel for what’s right.
Also, the finer the stone, the gentler your touch should be. Mistakes are more visible on finer stones. A knife might feel sharp after a #1000 stone, but lose its edge after using a #3000 if your technique isn’t steady.
Often, the angle changes slightly at the end of the stroke as the knife lifts off the stone—and that small wobble can undo your work.
So what’s the best motion? I like to say: sharpen in the opposite direction for maximum effect. Push or pull—it doesn’t matter much—as long as you keep the pressure consistent on the edge.
HOW LONG DO YOU SHARPEN ONE SIDE OF THE BLADE?
With proper sharpening, especially on good knives, you’ll notice a burr or “twist”—a tiny fold of metal that forms on the other side of the edge. You can often feel it with your fingernail.
The goal is to refine the blade until the burr disappears and the edge is centered and clean.
How burrs form depends on the steel and your technique. But there’s a common myth: that you should finish one side entirely before starting the other. I wouldn’t recommend that—it's a recipe for snapping the burr.
Victorinox knives are notorious for this. The burr breaks, and you lose the sharp edge you just created—sometimes it even leaves a visible dent.
Instead, alternate sides: 20 seconds on one, 20 on the other. That’s how you keep the edge even and avoid forming a weak burr.
QUANTITY OF WATER
Sharpening is a hands-on craft that’s all about technique. And water is a big part of it.
Water affects how the stone performs. Some stones only start working properly when the surface opens up and forms a slurry. If the surface dries out, the sound changes—and performance drops fast.
Some stones glaze quickly, but you can prevent that with a nagura stone and by using enough water.
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Sharpening is one of those skills you really learn by doing. You might quickly figure out how to get your own knives sharp, but when someone hands you a totally different blade—maybe made from a new kind of steel—it can throw you off. That’s why becoming a truly good sharpener takes practice, and lots of it. So don’t worry if things don’t go perfectly at first. Stick with it, find your own way, and enjoy the process. That’s the beauty of it—every blade teaches you something new.