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Our Technology

Handcrafted fine kitchen cutlery - at the peak of technical perfection.

Incredibly sharp edges and unmatched aesthetics set Kai Shun knives apart from every other kitchen knife on the market today. In the great tradition of Seki’s sword smiths, every knife is handmade by highly skilled specialists and requires at least 100 handcrafted steps to complete. Every day, the legacy of ancient sword smiths serves as inspiration to the artisans in the Kai factories. Kai’s 100-year-old tradition of blade-making excellence, combined with the newest technology and the most advanced materials, makes every Kai Shun knife a functional work of art.

 
Advanced high performance steels

  • Shun uses advanced, high-performance steel for our blades
  • Shun steel is hard so blades an be made thinner, lighter, and sharper
  • Advanced steel combines with a tradition of excellence to make knives "at the peak of perfection"

VG10 stainless steel
This premium steel adds cobalt for strength and hardness, vanadium for superior edge retention. High-performance VG10 needs minimal care to avoid corrosion, takes a wicked edge, and holds it for a very long time. Resharpening is easy—when the time comes.

VG-MAX
The latest in the VG line of "super steels," steels that have gained recognition throughout the kitchen knife industry as some of the finest cutlery steels available. It builds on the highly successful VG10 and is proprietary to Shun.

VG-MAX includes additional carbon to improve strength and durability. It has more chromium for wear and corrosion resistance. More cobalt enhances strength. Increased tungsten enables the steel to be very fine-grained—so the edge can be extremely fine and sharp. Molybdenum improves corrosion resistance and strength. Vanadium improves impact resistance and enables the steel to form vanadium carbides, which enhance cutting performance.

Shun hardens the VG-MAX in its knives to 60-61 on the Rockwell Hardness Scale, a standard measure of material hardness.

SG2 stainless steel
A proprietary “micro carbide” steel. The ultra-dense grain structure and purity of SG-2 make it both harder and yet less brittle than other high-performance steels. The result is a knife with the ability to take and hold an incredibly fine edge of unparalleled durability. Because of its combination of extreme edge performance and durability, SG-2 is considered by many to be the world’s best blade material for use in kitchen knives.

Traditional knifemaking style

Kasumi

  • A hard steel core is clad with a "softer" steel or steels to support it
  • Kasumi combines two or more types of steel to take advantage of the key characteristics of each of them
  • This method is similar to how samurai swords are traditionally made

 

 

Kasumi is a traditional Japanese style of knifemaking in which an extremely hard core of high-carbon steel is clad - that is, sheathed or covered - with exterior layers of another steel or steels. The somewhat “softer” or more ductile exterior cladding protects the inner cutting core. In Japanese, kasumi means “mist” and it is so called because the exterior steel can have a beautiful misty appearance when compared to the harder cutting core. Kasumi construction provides an ultimate mix of properties: an extremely sharp edge and ease of sharpening. This clad construction is similar to how samurai swords are traditionally made. Many Shun knives are layered steel or Damascus kasumi knives.


Composite blade technology

  • Combines the best characteristics of two steels in one blade
  • Steels are permanently joined
  • Patented, proprietary technology

 

 

Shun’s innovative Composite Blade Technology enables Shun to provide exceptional handcrafted quality at an amazing price. Here’s how our patented Composite Blade Technology works:

Shun laser cuts complex interlocking blade components from two different types of steel - like pieces of a jigsaw puzzle. Then we permanently join them into a single blade through a metallurgical process known as brazing. Brazing uses a third metal, a braze alloy, to join the two parts being brazed together; in this case, the two interlocking pieces of the knife blade.

You can see the brazed joint in a Shun Composite Blade as the thin copper line between the two blade steels. Is copper strong enough to permanently join steel blade components? In a word, yes. In fact, a brazed joint is as strong or stronger than the metals being joined. The brazed joint adds a decorative touch and enables us to use premium steel along the blade’s the cutting edge - where it belongs. It also means we can bring you Shun quality at a value price. If the whole blade were made of the high-cost steel, the knife could be prohibitively expensive. With Shun's Composite Blade technology, you can get all the cutting advantages of ultra-premium steel without having to pay an ultra-premium price.


Shun handle materials

PakkaWood
PakkaWood is a premium handle material made of genuine hardwood impregnated with resin. The resin makes it moisture resistant, strong, and durable. PakkaWood is intended for use in high-end products that see constant and hard use, especially  those used in wet environments. This, of course, makes it ideal for kitchen cutlery handles. Sanding and buffing brings PakkaWood to a beautiful gloss finish.

As with natural wood, no two pieces of PakkaWood® are exactly alike. Many Shun handles are made of PakkaWood. It offers our customers all the advantages of wood, including a beautiful look and feel, but since it's easy care and highly water resistant, virtually none of the disadvantages of untreated wood.

 

TPE
Shun Sora and Haru have TPE (thermoplastic elastomer) handles in traditional Japanese designs. The material is lightweight, durable, and provides excellent grip, balance & easy maintenance.

Tagayasan
The Kanso series features a handle made of a wood called tagayasan or wenge, which is sometimes known in Japan as “iron sword wood.” The handle contouring enables an easy chef's grip.

 

 

Layered Damascus

  • Shun layered Damascus is formed by layering different types of metal alloys together
  • The layers are forged into a single piece
  • The patterns are revealed by grinding then bead-blasting or acid etching the blades

 

 

Many Shun cutlery lines are characterized by the beautiful Damascus on the blades. Shun’s Damascus is formed by layering different types of metal alloys together, then forging them into a single piece. The process—and the different characteristics of the layered metals—create the rippling patterns in you see on the blade. The number of layers can vary; many Shun knives, for example, have 32 layers of metal on each side of a VG-MAX core. As Shun artisans grind each Damascus-clad blade from its thickest point at the spine to its razor-sharp cutting edge, they reveal the patterns. To bring them out even more, they bead blast or acid-etch each blade. When acid etched, the layered metals react to the solution in different ways. For example, carbon steel darkens, while nickel silver remains bright. Damascus protects and supports the extremely hard cutting core and enhances stain resistance.


Tsuchime finish

  • Tsuchime simply means "hammered"
  • Hammering creates air pockets that help food release from the blade
  • Shun knives with this finish are hand hammered, in the tradition of ancient Japan

 

 

In Japanese, tsuchime (Tsoo-CHEE-may) simply means “hammered” and you will see actual hammer marks on a tsuchime-finished blade. This finish does two things: gives the knife a look that is reminiscent of the handcrafting techniques of ancient Japan; and it creates tiny pockets of air that act as hollow-ground cavities to reduce drag and quickly release food from the blade. Shun’s gorgeous Premier line features a hand-hammered tsuchime blade finish as do some of our exclusive lines. In the tradition of ancient Japanese knife and swordmaking, Shun's tsuchime finish is created by hand hammering each blade.