Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Do most Japanese makers eyeball their heat treats??

  1. #1
    Senior Member rockbox's Avatar
    Join Date
    Feb 2011
    Location
    Longhorn Country
    Posts
    393

    Do most Japanese makers eyeball their heat treats??

    Every video I've watched of a Japanese knife maker, shows them eyeballing the temperature of the steel by the color of the glow. This even includes Murray Carter. I can't imagine this to be very precise. Would this explain the large difference in steel performance between one maker and the next? This is just my observation from the very limited number of videos I've seen and I could totally be on crack.
    "Insanity: doing the same thing over and over again and expecting different results." --Albert Einstein

  2. #2
    Senior Member
    Join Date
    Feb 2011
    Location
    San Diego, CA
    Posts
    4,214
    I've noticed the same thing but I bet it isn't as imprecise as it might seem nor would I be surprised if more "advanced" methods were less precise than we might expect. It's just hard to heat something up evenly, period.

  3. #3
    Senior Member rockbox's Avatar
    Join Date
    Feb 2011
    Location
    Longhorn Country
    Posts
    393
    I think its like people eyeballing the doneness of their steaks. It often produces excellent results especially if its a skilled cook, but it will never be as precise as using sous vide water bath or a simple probe thermometer for that matter.
    "Insanity: doing the same thing over and over again and expecting different results." --Albert Einstein

  4. #4
    Senior Member
    Join Date
    Feb 2011
    Location
    San Diego, CA
    Posts
    4,214
    That's sort of true but steaks don't glow. The color of the glow actually is very closely related to temperature. It's called a black-body radiator.

  5. #5
    I would imagine that most of the very experienced smiths in Japan learned from someone (or that person learned from someone) who learned how to heat treat knives when there were no means to taking the temperature of the forge or steel. So yes, they are able to eyeball it pretty accurately. But like TK said, it is more accurate than an untrained eye would assume, and it is hard to heat up chunks of metal evenly. And everyone has their own idea of what the ideal treat is.

  6. #6
    Quote Originally Posted by tk59 View Post
    That's sort of true but steaks don't glow.
    And if it does it is most likely well done

    DarkHOeK

  7. #7
    It depend on furnace.

    If it is a charcoal furnace eyeball the temperature is the only option.
    Yoshida san of Yoshikane Hamano said to me that he can see the temperature quite exact in the temperature range of 700 to 800 degree Celsius which would be the temperature for HT carbon steel.
    He said also he can not see the temperature for SS which would be around 950 degree Celsius.
    He use a temperature controlled gas oven for SS.

    Shigefusa only makes carbon steel kitchen knives and use charcoal furnace.
    He and his sons eyeball the temperature as well as how uniform the steel is before the quench.
    But his yield is not 100%.
    I get notice from Shigefusa when my order is in work but only after heat treatment.
    He does not make any notice that he began to forge my order because that knife can be lost to HT.

  8. #8
    Senior Member rockbox's Avatar
    Join Date
    Feb 2011
    Location
    Longhorn Country
    Posts
    393
    From the anecdotes posted on the interwebs, I would probably guess that makers such as Shigefusa or Doi are more particular about what passes as a good heat treat versus a blade they throw away than a maker such as Moritaka or Takeda.
    "Insanity: doing the same thing over and over again and expecting different results." --Albert Einstein

  9. #9
    it's the same as spark testing steel......alot of people think they analyze the steel but alot can and alot can't......ryan
    [SIGPIC][/SIGPIC]

    viva la revolucion !

  10. #10
    one thing you have to know is that the way you see color is dependent on how dark the over all room is too and any change in the lighting can cause problems
    i have befor seen makers at hammerins have failed welds or other problems cause there eye was not calabrated to the lighing under the tent

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •