How To Fix a Chipped Japanese Knife | Step-By-Step Guide

Author: Joost Nusselder, author of The Essential Japanese meal planner cookbook Updated January 7, 2023

You accidentally cut through chicken bones, and now your Japanese chef’s knife has a couple of chips in the blade.

They may look like a big deal at first but it happens even to experienced Japanese chefs. 

So this means you are looking for tips on restoring your chipped Japanese knife. 

If you’re a fan of traditional Japanese knives and want to restore your damaged blades to their original sharpness, then this article is for you! 

A chipped Japanese knife can be repaired in three steps. To give the knife a fresh cutting edge, you need to sharpen it. First, the chip is removed by grinding until it disappears. Then, the thickness of the blade is reduced, and finally, it’s re-sharpened. 

We’ll discuss when to sharpen, which tools to use, and why Japanese knives are so brittle. 

Check out our new cookbook

Bitemybun's family recipes with complete meal planner and recipe guide.

Try it out for free with Kindle Unlimited:

Read for free

A comprehensive guide to repairing chipped Japanese knives 

The bulk of Japanese kitchen knives is constructed from steels that rate 60 or higher on the HRC hardness scale. 

The main benefits of such steels are greater edge retention, a narrower blade profile, reduced weight, and the fact that, in contrast to popular assumption, they are actually simpler to sharpen than knives made of softer steels. 

Japanese knives are precise and extremely sharp, making them popular culinary utensils.

As with all things in life, having a knife made of incredibly hard steel has its disadvantages. The thin edge may chip if it is used improperly.

Something as basic as cutting through tough cartilage or chicken bone can make the blade chip instantly. 

Knives are made to handle substantial lateral (sideways) strains, yet they are fragile under large vertical forces.

Generally speaking, the steel is tougher the more sensitive the blade.

Fixing a chipped Japanese knife is simple and easy with the right tools and techniques – just because the blade is chipped, it doesn’t mean the knife can’t be salvaged!

Step one: grind the chip 

The first step to fixing your chipped knife is to grind it down until the chip is gone. 

To do this, a coarse whetstone is required.

Something like the Japanese King 220 Grit whetstone will do the job well because it’s coarse enough to really grind down the carbon steel blade. 

(view more images)

You can use a whetstone or a sharpening jig with a whetstone to do this.

• Set the knife at an aggressive angle which just means a wider angle than usual.
• With Japanese knives, it’s best to aim for an angle of 15 degrees, but in this situation, a 30-45 degree angle is preferable because it speeds up the removal of the undesired material.
• Since the point is not to make the blade razor sharp, the wide angle helps you remove the chip very quickly. 
• It’s important to maintain the same profile, or else you risk ending up with flat spots. 
• Use a Sharpie marker to trace the line of the profile over the chip. The line can be as thick or as thin as needed to go over all the chips. This will serve as a guideline, so you know where to grind. 
• Start grinding away at the steel using very light pressure. The general urge is to go in hard using a lot of pressure, but that can further damage the blade. Instead, go slow and stay consistent. 
• About 30 strokes must be applied until the chip or chips fade away. Try to grind the blade evenly from the heel to the tip. 
• Next, switch the blade to the opposite side and give this side about 30 strokes too.
• Continue doing this until your chip is entirely gone. You might have to switch sides a couple of times.
• To maintain a uniform profile, make sure to grind the blade’s whole length evenly. Double-check your work frequently. 
• Try to use the entire stone surface evenly because this technique is tough on your stone and will result in less wear.
• When grinding, it’s best to check frequently to ensure you don’t over grind the blade. 

Focus on correcting the damage rather than worrying too much about the particular angle you use or should be utilizing.

Any angle, as long as it leads you in the direction of redesigning the knife, is acceptable. 

I’ve reviewed the best whetstones for traditional knife sharpening here

Step two: thin the knife

Your knife is going to be very rough and chunky after the chips are removed through grinding.

Because it was sharpened at a coarse grit and aggressive angle, the blade isn’t smooth and razor-sharp just yet.

It may still cut through food but is more akin to an axe than a knife.

Because so much of the exposed core steel along the edge will have been removed during the grinding process, the Japanese knives’ famously razor-sharp edges are no longer present.

It’s best to thin out the knife to resolve this problem. This procedure will significantly improve your routine knife sharpening and chip repair skills.

This step is known as thinning out the bevel, making the whole knife glide smoother. 

Take out your 220 grit stone once more, and correct it precisely to make it flat once more by sharpening the bevel. 

This is crucial since a significant portion of the knife’s surface will come into touch with the stone. A flat stone provides a regular grind and few unwelcome scratches.

At this point, the knife’s bevel should be flat against the stone.

The intention is to expose part of the core steel along the edge by removing some of the cladding steel along the edges. 

Your middle and index fingers should be used to press down on the knife’s bevel while holding it in your dominant hand.

Though it should rest level against the stone, try to tilt the bevel toward the edge to concentrate pressure there.

Start cutting the stone with your knife while altering its position to remove steel from the sides along the entire length of the blade. 

Watch the cladding line to ensure that there is an equal quantity of exposed core steel along the whole length of the blade.

Although this can be time consuming, you must work on it until the removal’s grinding line, or “blade road,” is no longer visible.

Hone your knife and test it on some paper when you believe it has attained its original thinness.

Although there are still a few phases remaining in the procedure, now is a great time to review your work. 

Look for any remaining chips on the blade that you might have missed or any areas that still feel a touch thick.

If the edge feels harsh, don’t worry it can be fixed.

Step three: polish and sharpen

Once you have sufficiently thinned your knife, it will probably appear a little off and not as smooth as it should be.

There will be numerous scrapes from the gritty stone. That’s why the blade needs polishing. 

Repeat the previous process of keeping the bevel flat on the stone to make it nice and smooth once more, but this time use higher grits, exactly as you would in regular sharpening. 

The softer stones perform a little bit better for this application since the muck they produce offers a more equal finish. 

You can experiment with various grits, but to get the core steel to a higher shine, use the following combo: a series of 1000 and 2000 followed by a 4000. 

There is a lot of potential for experimentation here; to restore a knife’s original shine, you can use polishing pads, fine-grit sandpaper, or chromium oxide.

Although it requires a little patience, the end result is a stunning knife.

Now the last step is sharpening the knife again so that it’s razor-sharp.

You can decide to sharpen at a different angle than you usually do if you’re worried about the possibility of chipping the knife once more. 

While the majority of Japanese kitchen knives are sharpened at a 15-degree angle, you may find that a 20-degree angle will produce a stronger, chip-resistant edge.

Sharpen the edge with 1000 and 4000 grit whetstones but be gentle. 

Near this end point, a newly thinned knife doesn’t require much sharpening to become razor-sharp once more. 

Find the 8 best VG-10 steel knives for excellent edge retention & sharpness reviewed here

Can you fix a broken tip on a Japanese knife?

The same abrasive method is used as with the chips on the blade edges. 

When you have to fix the tip of the blade, you have to hone and grind away a lot more and it takes more manual labor. 

Basically, you have to grind down the blade until it forms a new tip.

Some people recommend using a diamond stone because it’s tougher than the whetstone. 

Can a chipped Japanese knife be fixed?

In some cases, if the damage is too extreme, you might have to take the knife to a professional knife sharpener who has professional tools.

In other extreme cases, the knife might be ruined for good and you’ll have to replace it. 

Luckily in most cases, sharpening it using a coarse grit stone will do the trick.

Because the blade must have a completely different form at the tip, the secret is to select a really high sharpening angle.

In order to produce a “new” tip, try to follow the chipped or damaged material itself with your sharpening actions. 

The damage smooths out over time until a fresh, round tip appears.

The knife gradually gets a tiny bit shorter, but it’s still great and functional. It’s as if the blade was never chipped in the first place!

Why do Japanese knives chip?

Japanese knives are made of a harder steel, making the blade thinner and more brittle than the average Western knife. 

There are many reasons why your Japanese knife may chip but usually there are a few common reasons:

• The blade cut into bone
• Cut on a rough surface like stainless steel, benchtops
• Too much pressure was applied from the side of the blade edge
• You accidentally bang the knife too hard
• Twist the blade while cutting
• Hit something fibrous at an angle

Using a Japanese knife requires special knife skills and techniques, and not using those skills can lead to blade damage.

When slicing or chopping food, there are certain motions you must follow to avoid damaging the blade. 

However, the bottom line is that Japanese blades are far more sensitive than most Western blades, and since carbon steel is much harder, it’s also more brittle and more prone to chipping. 

Also read: How to clean & remove rust from Japanese knives [simple tricks]

Can a chipped Shun knife be repaired?

Shun is a premium Japanese knife brand. Their knives can also be repaired when chipped. 

If the chips are small (2mm or less), you can grind them away slowly with a coarse whetstone and then sharpen the edge again. 

If the tip of the knife breaks, it takes more work but it can be repaired too.

The material from the spine and cutting edge has to be removed, and the tip can be re-formed.

Is there a risk to damage the knife even more when fixing a chipped blade?

While there’s a certain risk to damage the blade further, it’s unlikely.

When you’re sharpening the blade with a coarse whetstone, you are essentially removing the chips by stripping away the steel layers.

There’s a risk that you will make the tip very dull. Another potential risk is that if you apply too much pressure you can strip away too much steel. 

Conclusion

There’s no need to panic if you’ve chipped the blade on your favorite santoku knife while cutting meat.

It can happen since the Japanese blades are more sensitive and prone to breakage. 

The simplest method of fixing a chipped Japanese blade is to grind the chips down on a very coarse whetstone, then polish and sharpen the blade until it is razor shape again. 

You’ll have to use a high sharpening angle when grinding the chips away. With this method, you can pretty much fix any damaged Japanese knife and save money. 

Keep your Japanese knife collection in nick by storing them properly with (magnetic) knife holders or stands

Check out our new cookbook

Bitemybun's family recipes with complete meal planner and recipe guide.

Try it out for free with Kindle Unlimited:

Read for free

Joost Nusselder, the founder of Bite My Bun is a content marketer, dad and loves trying out new food with Japanese food at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.