Kai Shun - New Zealand's Official Home

FAQs

What is Rockwell Hardness Steels and what does it mean?

The Rockwell scale provides a convenient way to compare the hardness of two materials, such as types of steel. It measures hardness based on the depth of penetration of a diamond cone pressed into the material at a constant pressure. Put simply, the higher the number, the harder the material.

In general, Shun hardens VG10 and VG-Max steel to 60-61 Rockwell and SG2 to 61-62. An increase of 1 degree Rockwell equates to an increase in hardness of about 10% as well as an increase in edge-holding ability. These degrees of hardness enable Shun knives to be thin, hard, and precise without being overly brittle.

What is the difference between Japanese and German steel knives?

German (and other Western-style) knives tend to be heavier and made of “tougher” but “softer” steel. They are also generally made from thicker blade stock, which means it takes a bit more pressure to slice through foods. What’s more, these knives are typically sharpened to a wider cutting angle (20-25° on each side of the blade), again requiring more muscle to cut through foods. Because of the “softer” steel, German steel knives will also get dull faster and require more maintenance. Many cooks find that they need to hone their knives before each use.

Japanese steel knives are generally lighter in weight and are made of thinner, harder steel. Due to their harder steel, the blade stock can be thinner and the edge more acute—that is, sharper—than a comparable German knife. Shun knives, for example, are sharpened to a 16° angle on each side of the blade. The lighter, thinner blade makes Japanese steel knives like Shun extremely agile, precise, and can even be less tiring to use.

This is not to say that German steel knives are “bad.” (In fact, the softer steel enables them to take a bit more edge abuse.) It’s just that Japanese steel knives are different creatures. You may find that you need to refine your knife technique in order to take full advantage of the light precision that Japanese steel knives have to offer. For instance, if you’re used to simply pressing downward to make a cut with a German type knife, with a Japanese knife you want to make sure you slice by moving the knife forward or backward. This avoids crushing the food, enables the thin, light blade to glide through whatever you’re cutting, and helps you make a very precise cut.

Is there anything Shun knives shouldn't be used on?

Please do not use Shun knives on bones, joints, frozen foods or very hard vegetables like pumpkin. Most Shun knives are designed for precision slicing rather than crushing down through hard materials. 

How can I help maintain the life of knife?

If you use your Shun knife correctly, it can provide you with a lifetime of service. Yet using your knife correctly isn’t only about how to maintain the edge or how to sharpen the blade; it’s also about how you use the knife on a daily basis.

Please do not push straight down on your blades. Not only will this result in arm fatigue for you, it can also be hard on your blades—and could result in chipping. When you cut, it’s important to use a “locomotive” motion. Move the blade in either a forward or backward direction. By pushing the blade forward when you chop, rather than pushing straight down, the blade does the work instead of having to use your muscle to cut. The same applies to pulling back on the knife. This slicing motion will cut down on unnecessary muscle strain and keep your blade in excellent condition.

What is the difference between honing and sharpening?

The honing steel is strictly for honing, that is realigning the blade's edge and won't take material off your blade. From time to time, your knife will need to be sharpened either with a whetstone, an electric sharpener or a professional to give your blade back its sharp edge. 

See the Sharpening and Honing page under Use and Care for more information.

Can I wash my knife in the dishwasher?

We recommend that you do not wash your knives in the dishwasher. Here’s why: The dishwasher can be hard on all your dishes, but it can be especially hard on knives because they tend to get knocked around during the cycle. Conversely, sharp knives can put “dings” in your dishwasher, too. In addition, when you wash different grades of metal together, brown spotting may occur on the higher quality metals (such as Shun blades). These spots can be difficult, if not impossible, to remove. Finally, many dishwashing detergents contain corrosive agents, such as citrus extracts. Not only can this cause unnecessary wear on your dishes, it can also cause pitting or corrosion on your Shun knives.

For all these reasons, we recommend that you protect your investment by handwashing your knives with a gentle dish soap.