Why honyaki knives so expensive, even if made with a single steel like cheap stainless knives ?

A customer asked about the wave line on a popular kitchen knife,

“Hello, i have a question and can´t find the answer at the tutorials. There are two blade structures of traditional japanese knives.
  Kasumi (cheaper)
  Honyaki (very expensive)
There are some cheaper japaneses knives made with stainless steel. I think they are made with one steel like Honyaki knives. Is this right? How can they be so cheap? Is it because of the stainless steel? Is the hardening process of stainless steel different to carbon steel and much more easier ?

For example: Masahiro Stainless Japanese-style Deba Knife 120mm
I can see no Hamon.”

It seems an issue that some are concerned about. The following was our answer, hoping it would be helpful for him.
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First, we must discuss things in high-carbon steel world.

“Honyaki” knives are forged from one single material of steel, generally high-carbon steel called “hagane” (blue or white steel) .
The finest “Honyaki” is differentially-hardened and their sharpness is the longest lasting of all Japanese blades.
They are extremely difficult to make right forging and rapid quenching which require a high level of skill and experience.
Also, the number of skilled blacksmiths who can handle this process exist very few today. That’s the reason why they are very expensive.
(Even if the stainless knives are made of a single material of stainless steel, they are not “Honyaki” in the proper sense of the word.)

On the other hand, “Kasumi” are made from two materials, “hagane” and soft iron “jigane” forged together.
This style of knives do not necessarily require high skills for processing as the honyaki.
So, the Kasumi offers a similar cutting edge to a honyaki blade in high-grade knives at a reasonable price.

Second, stainless steel knives generally doesn’t require such difficult forging and quenching process as hagane,
that means they can be processed with less skills to achieve a kind of mass production. That’s why the stainless knives are manufactured at a much cheaper cost.

Of course stainless knives made of two materials like Kasumi are very popular and have a hamon on the blade.
The Masahiro Stainless Japanese-style Deba Knife is made of a single stainless steel, which does not have the “Hamon” as you mentioned.
(There are two ways that “Hamon” is created, one is boundary of two materials like “Kasumi”, another is at special harden process of “Honyaki”.)
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