Tamahagane Knives?

Anyone have experience or information on Tamahagane steel used for chef knives? I saw some Yoshimitsu's on CKTG, but I'm not into the blade style of that knife.
http://www.chefknivestogo.com/yotacugy24.html

 

I saw a cool documentary on the way they make the steel. The guys that do it stay up for like two days straight making it. It's a really cool tradition that the craftsman are trying to keep alive.

 

A short WIP link about making a knife from bog iron (it's in Russian, but there isn't much to read there). Not related to Tamahagane, but the idea is similar

 

Cool pics, does he say if that steel he made is more brittle than modern carbon steels (blue steel, white steel)?

 

I doubt that that steel could really compete with any modern factory made steel, but that's just my own speculations, as there are no details about resulted hardness, abrasion resistance or any other parameters of steel. That was more of an illustration of the idea of forging a knife from some locally mined ore.

 

A couple years ago at my Hammer in we did something similar and smelted down clay iron ore from a river in Michigan.. That turned into what is called a bloom. Then the bloom is separated and further processed and reduced until its homogenized.. At this point. the material was combined with meteorite that had also been reduced and worked for hours to prepare it for the billet.. Was alot of fun.

I have yet to try the steel as a kitchen knife. But firmly believe it to make a VERY serviceable cutting tool!!

 

Meteorite? Damn thats exotic. Must be an expensive blade if that billet was used, lots of labor cost. Very cool!

 

Iron meteorite can be had pretty cheaply if one's not looking for collectible or decorative (e.g.widmanstätten pattern which is admittedly pretty neat). I've used it a few times too, though I always thought it a bit silly.

 

The idea was to use stuff found naturally. to produce something functional. I still have not used the resulting piece of steel. I hope to do so at the bext HHH Hammer in!! sort of a continuation..

The cost of a meteorite vary greatly, Both depending on where its found. and if its documented.. etc. For my purpose I can select the lower cost options, Yet its still sold by the gram weight. And it adds up fast.. considering ya need about 3 to 4 lbs to start with. just to get enough usable material to make a billet large enough to be a knife or 2...

Your right on that alot of the "cost" are in labor. to process and refine the stuff.

Blessings
Randy

 

ave Tamahagane used to build the knife, and the polishing looks like it was done by a 2 year old, and the sandblasted blade road?

Sandblasted finish and tamahagane?
Sandblasted finish and tamahagane?
Sandblasted finish and tamahagane?
Sandblasted finish and tamahagane?

ave

 

I was present at the HHH hammer in, discussed above & the making of that meteorite billet was one of the coolest things I have ever seen! Way cool!!!

 

That's some expensive junk 'eh?

 

I might be very wrong here, but I dont feel like its about the price.

Imagine that? Some old farts sit for 3 days without sleeping to produce it, highly stressed, its kind of sacred to them, and then they let an anonymous maker do an ugly blade with THAT kind of finish?

Id be surprised if thats the actual case. Damn I would.

 

"Official" tamahagane, recycled old steel of variable quality, and various small bloomery techniques that use the name tamahagane are not something to always take seriously.

 

I get the mystique and understand people wanting them for that value. I would be curious to see what you'd get mixing well made Tamahagane with makers such as Shigefusa, Heiji, Kato, etc...

...guessing since they choose to use what they do: special Iwasaki(sp) carbon or Kato's special mix (?) that maybe it's not so much as nice a steel for kitchen knives as what they choose?

 

several years ago I and several others put together a smelt using specular hematite iron ore. After ten hours of running the furnace we recovered a an 80 pound bloom of steel. after several folds of a small piece of this bloom the steel seemed homogenous so it was sent to a lab for analysis. composition came back as ;

iron 98%
c 1.2%

and trace elements of tungsten, vanadium, manganese, silicon, sulfur and some others that I cannot remember. so it was essentially W1 steel


water quenched blades where no different than water quenched blades of other simple carbon steels for brittleness, toughness or edge holding that I have made

 

Sounds like relatively clean W1 steel...but then again, that's why you order W1 vs 1095 anyhow...is for the better controlled tolerances I guess.

I recently got into a 'discussion' with a gentleman on my youtube channel. He believed that Japanese white steels have 'endless' potential, and that the fact that five to ten degrees difference in heat treat temperature totally changing the end result of said steel was a GOOD thing. His reasons for this were a Murray Carter video (taken completely out of context), and that the white steels were 'manufactured to match the steel used in the greatest bladed weapons in the world'. As if that means anything in today's world. I'd love to see a tamahagane katana put directly against one of Howard's L6 bainite blades lol. I'm thinking we'd quickly have a two piece tamahagane blade!!

Regardless of all that...he had no understanding that the alloys we introduce into simple steels are there for a reason...and by taking advantage of them we can have virtually no loss in sharpness, while gaining significant wear resistance (read: edge holding). Carbides are wonderful things when you know how to manipulate them in regards to size...along with how to get them OUT of the grain boundaries. For this reason alone I love my W2...and am looking forward to playing with the Japanese blue #2 I picked up from Aldo recently.

Anyway, tamahagane is all great for modern nihonto art pieces...but for a kitchen knife? Unless you are looking for a novelty item (and probably a very expensive one), you're better off with pretty much ANY modern manufactured steel.

 

I have to admit, I dont have a clue or idea on carbides and such, nor I care about them. That is why different folks choose different professions and specialize themselves into a narrow fields.
Still, having said that, I am very very sceptical about the "no loss in sharpness". IMHO and WADR [and CIA and FBI] that is just sellers talk to me Cris.
I sharpened some blades in the famous blue super[some reputation on the forums] and each and every knife made out of it had a gummy feeling on the stones, like a piece of rubber sliding off of oiled ceramics. And the difference in sharpness was, well, it was something, how to put it?

When a Masamotos white is sharp, man I have to watch myself.
You know, this feeling that if it hits you, its gonna go deep lol. Its the fear of getting chopped in two!

??ump
Theres no such respect when AS knife is in use, its sharpness might only be described as boring.
So when I hear things like no loss in sharpness Im like "badong red alert ":BF
Just sayin'

Look around, 90 percent here does

 

I have never worked with blue steels. The steel I'm talking about is American AISI W2. The batch I'm using now is simple iron, .98% carbon, a smidge of vanadium, and a smidge of chromium. Very low manganese...and whatever other trace elements there are. It's an engineered steel yes...but it's still a simple steel. It works well on the stones...gets very sharp, and because there are alloying elements (vanadium and chromium), the free carbon above the eutectic point will grab them and make carbides. My job as the bladesmith is to make sure those carbides are tiny, evenly dispersed, and NOT in the grain boundaries. If I've done my job...scary sharp edges are very real....and they will hold on to that edge longer than comparable geometry white steel blades.

Perhaps it's my level of sharpening skill...perhaps it's the heat treat on the few white steel knives I've handled. But I can honestly say they got no more sharp than my own W2 knives...and the W2 edge is more durable.

 

Alloying elements have pretty complex effects in steel and relatively subtle differences can have pretty dramatic consequences in transformation curves and within the microstructure beyond forming carbides. When folks say things like "adds toughness" or similarly sweeping generalizations, I cringe a little.

With the ways most of us have learned to heat treat steels (and the technology most of us use), simpler low-alloy steels make a lot of sense for edge potential, but that includes a fair range of steels such as W2 and 52100 in which the alloying elements are not dominant carbide formers and have other effects.

AS has more working against it than merely the presence of carbide formers, IMO.