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Post by Deleted on Jan 14, 2010 18:40:20 GMT
now I'm curious to have this one answered definitively... or at least with some sort of professional information source. what modern steel is comparable to a 400 year old blade? so far what we've got is I have heard that 1070 tends to have about the same amount of carbon meaning it can become about as hard. the swiss powder steels require some sort of folding work and tend to produce patterns of grain in the steel that can be similar to tamahagane (but powder steel is expensive) and the typical carbon content of an old blade is hard to describe, as most were made in multiple parts from different grades of steel to begin with. If you are looking for a generally comparable monosteel then believe it or not you are looking at 1065 (which is why I use it a lot) and in my experience 1065 responds best to full on traditional methods. If you are using the adaptive methods used by most western smiths then your best bet is 1070 or 1084; if trying for more extreme traditional methods then 1045 or 1050 is your best bet. and My understanding is that the tanahagane was anywhere from 0.9% to 1.5% carbon. There are various steels and irons (as well as other crap) in the kera and it was up to the smelter and smiths to determine what was best for each part of the blade. So the answers we have so far are 1065, 1070, and anywhere from 1090 to (1150?) steel should be similar... at least in carbon content. Seems a little confusing... but then, carbon content would likely vary wildly depending on who smelted the stuff. Not being a metallurgist myself, I'm not sure what the other differences would be from the ancient stuff to the modern stuff... such as old refinement processes. if done well, is the end result different from what we have today, or is the difference all really all in how the blade is forged?
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Post by Deleted on Jan 14, 2010 21:45:15 GMT
Remember, tamahagane is a type of steel, not a spec. Each production produces a wide variety of carbon content and only a portion is deemed good enough for sword usage. If things don't go correctly, none is usable and it is put to other uses.
The smith picks the best and sorts and stacks various grades (carbon content) to forge together to make the blade of the stuff that is usable. It stands to reason that the carbon content varies from blade to blade.
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Post by Deleted on Jan 14, 2010 21:48:51 GMT
so get in touch with these guys: ky.abana-chapter.com/ ; membership is $15.00 a year You have Larry Zoeller in your back yard: www.zoellerforge.com/ ; give him a jingle $400 bucks for a five-week course is NOT a bad price though. About the bad shoulder: The VA removed both of my collarbones a few years back and hammering does not bother me. Hammering (with good technique) should not bother you either. I'll have to think on it, but I'll definitely check those links. There's a certain satisfaction in being able to make things with your own two hands that you can't really get any other way. Plus I'm big into learning skills that have almost been lost. Now, I just need to figure out if the hammering technique I used to use as a mechanic will work, or if it needs refinement. If I can do the class y'all know I'm going to be going photo post crazy, but this might take some time.
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Post by Deleted on Jan 15, 2010 19:01:05 GMT
Dan, what is cementation in terms of work done to an iron bloom?
M.
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Post by Dan Davis on Jan 15, 2010 19:22:46 GMT
Brett, Old-style charcoal blooms using the European methods give essentially the same result as you get with a tatara; the only real difference between the old European and old Japanese methods is that the Japanese would complete the smelting and cementation processes in one step, where in Europe it was typically done in two steps and often hundreds or thousands of miles separated the two processes.
Neither of these methods is anything like the bessemer converter process used today. I'll have to have a look at how it was done in Europe, never looked into that side of things, but as my 'passion' (or should that be addiction) is moving into European blades it makes sense to see how they were made and how the ore was smelted in the first place.
Thanks for some extra commentary Dan, you've given me another research project
BrettBrett, While doing some housekeeping in the Smithing forum I ran across the following thread: /index.cgi?board=swordmakingstickies&action=display&thread=14232Take a look at the second video, ignore the non-technical fluff from the narrator, and concentrate instead on what the late Paul Champagne has to say about making an old-fashioned European bloom.
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Post by Dan Davis on Jan 15, 2010 19:36:32 GMT
Dan, what is cementation in terms of work done to an iron bloom?
M. Cementation: Any metallurgical process in which the surface of a metal is impregnated by some other substance, especially an obsolete process for making steel by heating bars of wrought iron to red heat for several days in a bed of charcoal. During the early ages of European history when each smith produced his own bloom(s) this was really not part of the process. Check out the video I referenced in my previous post; you can see an European steel bloom and it's resultant product. Later, iron was produced using a cupola furnace and poured out as elemental iron. The elemental iron was then hot hammered ( wrought) into bars. These bars of pure iron were then shipped across Europe to various users. Please note, these bars were typically 4" x 4" x 36" and weighed hundreds of pounds. When a bladesmith received it he would divide it up and then had to run through a lengthy cementation process in order to make good steel from the wrought iron bars. Cementation as a process is essentially the same as case hardening but done at slightly higher temperatures.
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Post by Deleted on Jan 17, 2010 8:19:53 GMT
Off topic but kind of related. I once read a science fiction story about a planet settled but Japanese and the modern versus ancient steel question came up. All the aristocrats had their ancient family swords and everyone else had to use modern steel and even though the old swords could be chopped apart by a new one the new swords were looked at with contempt.
On topic I am interested in this too. I want to try my hand at knife making and then maybe forging my own sword and even though I want try making my own folded steel blades, or maybe try shaving a steel block and then re welding the shavings, to use it as lamination on a modern steel core for the cutting edge. That way you could sort of simulate the look of an old sword.
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Post by Kilted Cossack on Jan 18, 2010 2:36:46 GMT
Guys:
This is a great thread. Thanks especially to Dan and Sal---I've learned something, and I give thanks.
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