Why Do Knives Chip?

One part of kitchen knives that sadly can't be avioded during continuous usage of them is the blade chipping - especially if the blade is sharpened quite thin as Japanese knives often are.

We know there's many people both amateurs and professionals alike that have had to encounter a chipped knife. A thin knife is an extrmely brittle knife, so it's somewhat unavoidable. But you can not only mitigate chances of this occuring, but save chipped knives and continue to reuse them as well! This article will show you how to prevent knives from chipping where possible - but of course this won't make your knives chip-proof That comes down to how you use and care for them.

Why do knives chip?

Most blade chips come down to using a knife incorrectly. This is why our 6 Tips of Caring for Japanese Knives article has multiple tips dedicated to cutting angles and styles. We refer to incorrect usage here as any kind of usage that applies an unnatural or unexpected impact on the knife. We've broken this down into three broad concepts:

  1. When a force stronger than expected is applied
  2. When force is applied from the side
  3. When cutting frozen food


When a force stronger than expected is applied

This category is for when you cut ingredients that are too hard. This is commonly items like fish bones and shells, and some really tough root vegetables.

It's difficult to cut such hard items, so if you use the knife to do so by hitting or pushing the knife from above there's a chance you'll chip it.

This can also apply to how you cut onto a cutting board. If you cut with too much force, your knife will strike and effectively try to cut the cutting board. Those boards are generally harder than the knife, which can cause it to chip. With a sharper knife your cut can be smoother and thus you can avoid this. We strongly recommend to avoid cutting with overly heavy amounts of force that means you strike the cutting board too strongly, or use a softer wooden cutting board material like hinoki or gingko. This is also a good tip to keep your knife's sharpness levels higher for longer. Read our article on hinoki to learn more!

When force is applied from the side

This category is for when you cut in anyway that is twisting your knife.

When cutting something with a harder skin such as a pumpkin, the blade will generally have trouble getting through it unless it's extremely sharp. If you try to pry through using your knife, the blade may chip. This also applies if you're using your knife for any other purpose it's not intended for - like opening a can for example.

A kitchen knife has a lot of strength when it comes to vertical force, but due to how thin the blade is, especially around the cutting edge, they are very susceptible to damage from horizontal force.

When cutting frozen food

This category is as it says, occuring when you cut frozen foods such as meat. Frozen food is often very hard and difficult to cut, meaning your knife may bend during cutting and thus chip. In this case, the chip is likely to be very large as well - sometimes more than 5 centimetres end to end!

Therefore, be absolutely sure not to use your knives on frozen foods unless the knife is specifically designed for it. Even if the surface has thawed, the interior might still be frozen and could damage your knife. Knives, especially high-quality ones that are well tempered chip shockingly easily at low temperatures. While knives with large chips are savable too, it does mean your knife will lose a large amount of lifespan, so please be very careful with frozen and thawed foods.

Other possible causes of chipping

While chipping often occurs due to usage of the knife, this isn't always the case. Other external factors can cause a knife to chip, or lose stability and thus performance. We've listed a few examples below, but this list is not exhaustive.

If the rust has penetrated the knife (pitting corrosion)

This is when a knife is neglected and gets rusty - and is especially the case with stainless steel knives.

This rust penetrates into the blade and pitted downwards, leaving a chip on the blade even after it's been sharpened due to internal integrity failing.

In the picture below, those white dots on the knife indicate pitting corrosion. We have an article dedicated to why knives might rust if you want to learn more.

If the knife is sharpened too thin

Knives are sharpened to make them sharp of course, and some people really focus on that and sharpen the blade extra thin as a result to get peak cutting performance. This makes the blade extremely brittle, and even though it will cut very well it also makes it susceptible to chipping from even the slighest impact or misuse. Many people often sharpen a "secondary edge" into their blade to grant a little more stability to the knife. You can find out more about that in our santoku sharpening guide!

If there is a problem with the knife's heat treatment

While this cause is more unlikely, it is possible for a blade to chip more easily if there was an issue with the heat treatment during its production cycle.

Knives are hardened by blacksmiths, but if they aren't tempered properly the metal structure of the knife becomes very brittle, causing chips over time.

This is a manufacturing issue, and something you should contact your manufacturer about if you suspect this has happened. Be sure to always read your guarantee and warranty information that comes with any knife. Not only will it tell you how to report faults like this, but it can also sometimes have recommended methods of using the knife in them to keep them from chipping.

Chipped knives can be saved!

I'm sure you'd get quite shocked if a knife chipped while you were using it.

Some people even say when that happens, that it's time to throw the knife out and replace it. We strongly disagree with this.

If you sharpen your knife properly, you can restore it back to it's original condition (or at least near it) regardless of whether the chip is small or large. However, you need to know precisely how to sharpen...

...Or contact us! A large chip does take various whetstones, patience and a lot of time and effort. We do professional sharpenings and repair work at our store so feel free to contact us if the chip is too large or complex to recover and we can bring the life back into your knife!

Don't throw chipped knives away! Send them to us for repair, or for memorial service if you are finished with them