Lifes little things

[Ooitame]

I find sometimes, the smaller things that draw me to Nihonto, are quite joyous.

This is a thoughtful gift from my brother, with many thanks. Looking at Tamahgane, not only did it draw me closer to Nihonto, the forging process and knowledge/skill needed, but to family as well. For this,  I am thankful! I wish, I could capture the middle stone's deep sea blue, or midnight sky color, and imagine the possibilities... beautiful. Just thought I would share. Happy and safe Holiday season to all. 

 

 

[Ken-Hawaii]

That blue tamahagane is really high-quality! Good collection.

[16k]

Nice! Where did you get these? I'd like to get a sample at some point.

[RichardP]

Wow—the notion that steels from different regions produce swords with their own color hues seems really plausible, looking at the raw material...

[dwmc]

  On 12/8/2020 at 12:40 PM, 16k said:

Nice! Where did you get these? I'd like to get a sample at some point.

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https://www.ebay.com/itm/IN-HAND-TAMAHAGANE-TATARA-NBTHK-1st-Grade-60g-with-Tung-Box-FedEx-DHL/313334756394?hash=item48f434f42a:g:BJkAAOSwnNtfz3X8

 

Dave M.

[16k]

Thank you for the link!

[Surfson]

Here is one from Matsu-kaze.  It's less tamahagane but cheaper.  Just bought one.  

 

https://www.ebay.com/itm/274592882983

 

[Vermithrax16]

Super nice gift!  Thanks for sharing.

[Andi B.]

If you have luck, some of this small pieces from the Nittoho Tatara have nice colours...

[Bugyotsuji]

They were presenting everyone with a beautiful chunk of tamahagane at the first NBTHK national meeting in the Keio Hotel some years ago. From their tatara in Shimane. Still have mine somewhere, and yes, it does have a lovely blue spot or two in it, like Andi's above. 

[paulb]

I was fortunate enough to win my example in the annual draw here (thank you Jesper) and still use it when doing presentations about sword construction.

[kissakai]

I was also fortunate enough to win my example in the annual draw here (thank you Jesper) and still use it when doing presentations about sword construction.

I marvel at the colour and how heavy it is

I miss the Christmas Draw

 

[Brian]

I am trying to work out the logistics of running one, given the PP limitations on raffles.

[ROKUJURO]

  On 12/8/2020 at 3:12 PM, RichardP said:

.....the notion that steels from different regions produce swords with their own color hues seems really plausible......

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Richard,

that would be a nice theory, but in reality, the colours have nothing to say. They are just annealing colours, and you can produce them on any polished surface of any simple iron with a gas torch. You can even produce them on titanium, looks nice!

If you imagine how iron/steel is being produced in a TATARA, you will see that the furnace is torn apart while the KERA (bloom iron lump) is still hot. The HITACHI TATARA produces about 2,5 tons in one go, so you cannot wait until it has cooled down and cut the block in slices afterwards! The small pieces still have temperatures between 200 and 500 °C, so they show these tempering/annealing colours. Beautiful, and a good reason to call it 'jewel' cutting edge steel (TAMA HA GANE)!

[cju777]

Christmas stocking stuffer idea found. Thanks for sharing this!

[Ooitame]

  On 12/9/2020 at 11:55 AM, ROKUJURO said:

Richard,

that would be a nice theory, but in reality, the colours have nothing to say. They are just annealing colours, and you can produce them on any polished surface of any simple iron with a gas torch. You can even produce them on titanium, looks nice!

If you imagine how iron/steel is being produced in a TATARA, you will see that the furnace is torn apart while the KERA (bloom iron lump) is still hot. The HITACHI TATARA produces about 2,5 tons in one go, so you cannot wait until it has cooled down and cut the block in slices afterwards! The small pieces still have temperatures between 200 and 500 °C, so they show these tempering/annealing colours. Beautiful, and a good reason to call it 'jewel' cutting edge steel (TAMA HA GANE)!

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In general I agree, however when comparing swords side by side minute differences can be seen... atleast I think.

[ROKUJURO]

Eric,

this is due to the different treatments in polishing. See under KANAHADA.

The annealing colours are minute layers of iron oxide - a few millionth of a millimeter - which build up under the influence of heat and - of course - air. The colour can (roughly) indicate the temperature the iron/steel was exposed to. This feature is used by the smith when tempering his tools and knife blades.

[Surfson]

Jean, does the color reflect (pun intended) the degree of oxygenation of the iron or are there more complex structures?  

 

[Bugyotsuji]

  On 12/9/2020 at 3:36 PM, cju777 said:

Christmas stocking stuffer idea found. Thanks for sharing this!

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You might need an extra large thumb tack, Chris.

[ROKUJURO]

Robert,

in my experience it is a very superficial phenomenon and does not affect the quality of the steel, so you cannot really speak of 'oxygenation'. The colours are not durable, so when I leave them on the steel surface of a tool, they will fade and eventually get rubbed off by use.
 

[Surfson]

 I see, so they are just residue from the combustion of the natural gas then.  Interesting.

[ROKUJURO]

Robert,

there is no natural gas involved except air. The hot iron/steel surface reacts with the oxygen and as a result produces these ultra-thin layers of iron oxide. The longer the metal is exposed (or the hotter it is), the thicker the layer. The colour change is related to a temperature/time effect.

[Ooitame]

I will have to agree to disagree, sword temp. and the cooling process oil vs water vs time, plus clay treatment, with sub component/elemental materials will have an effect of crystalline structures and their hues. From Jiange is the key "Jigane can show hues and its appearance, at least as far as koto blades are concerned, make it possible to draw conclusions as to where the sword was made.".  Polishing can certainly have an effect, but I have found koto blades seem to vary from a blueish to gray. Blasting a torch or high temp. to achieve the effect seen above, can easily be removed. This does not happen with something that has been polished, possibly many times. 

[cju777]

Despite a circuitous route from Japan to the US east coast then back to Japan and ultimately Thailand my "Christmas stocking stuffer" Tamahage finally arrived. I opted for the smaller box. Put it with on a bookshelf for some size context. Pretty neat addition to the collection! Displays really nice and one of the pieces has some interesting purple and green hues to it.