real old school

[Omega]

this may be a stupid question but back in the samurai time or that of the romans how did they go about tempering their swords obviously not in the household oven, so how did they do it


thx

bill

[Ray Rogers]

That's an interesting question. Unfortunately, I don't know the answer but I bet someone will come along who does.

But, I'd like to venture a guess. My guess is that in most instances they probably didn't temper the blades. The Japanese swords were clay tempered which gave them hard edges and soft backs thus reducing the need for any further tempering. Further tempering might have helped but maybe it wasn't essential.

I'm no expert on Roman history either but if I recall correctly the Roman legions were armed with swords made from copper or bronze for most of the time Rome ruled. Towards the end, the found out about iron but I don't think (dangerous ground here!) that they ever had steel swords. So, they had no need of tempering.

OK, now somebody gets to shoot me down with a history lesson....

[Omega]

i figured as much with the samurai the other swords of early times are the one im confused about as well hopefully some of our historians will give us a little lesson
Bill

[J.Arthur Loose]

The European Iron Age is generally considered to have started around 600-700 BCE. This isn't to suggest that iron was unknown before this date, as the Ancient Egyptians have left us some iron implements and the Hittites had been smelting from about 1700 BCE...

The Romans definitely had iron *and steel*, the question is how common it was:

Pliny [ CE 23-79 ], in his Natural History, Book XXXIV, describes the process of tempering used by Roman blacksmiths. Although his explanations are incorrect, the fact is made that a hardening process was known and used on iron based tools. Pure iron, even very low carbon wrought iron, cannot be hardened.

- Steel in Ancient Greece and Rome
http://www.mri.on.ca/steel.html

Steel production was really underway at the time in India, where they produced a material called wootz which came to be traded in a city called Damascus. Wootz has an unusual structure that results in a very strong & sharp blade with a characteristic surface pattern. It is because of the trade in Indian wootz during the late Roman Era that we still call our pattern welded blades 'damascus'.

Indian steel production during the Greco-Roman Era:

It is suggested by Parr[18] that real production of steel began as early as 500 BC in India. This material was referred to as wootz. By Alexander's time the production of wootz was a well established two step process using the crucible method. Two methods could be used, conversion from a cast iron form or conversion from a wrought iron form.

-ibid

Anyway, I couldn't find Pliny's explanation for the tempering technique itself... but easy possibilities include small kilns, tempering over open flame, laying the blade along a hot surface such as a heated bar of metal or even stone. The temper can be relatively accurately gauged by the tempering colors. I can think of one Norse Saga ( 1000 CE -1200 CE ) where a man escapes an arson and notes that his blade has turned blue from the heat... he then claims that he'll '...reharden it in the blood,' of those who set the fire; indicating an understanding of the effect of tempering colors on the hardness of a *hardened* blade.

I think there's a huge tendency for us to underestimate the best quality and understanding of steel blades in the Ancient & Dark Ages. Our craft was surrounded in secrecy and many people produced serviceable un-heat-treated iron / steel blades while just the next town over someone jealously guarded the secret to producing consistent high quality steel & heat-treating it well. Personally I think the addition of carbon to a smelt is an accident waiting to happen as it's part of the natural process of heating ore with charcoal. I also think that hardening the steel is an accident waiting to happen since quenching is a natural part of the forging process.

Apparently, some Saxons were making steel a thousand years before the Industrial Revolution 'discovered,' the same process:

http://www.brad.ac.uk/acad/archsci/d...amrg/steel.htm

I wonder how many other examples of complex metallurgical understanding have become lost secrets? Anyway... thanks for prompting me to find some cool links!

[Ray Rogers]

Good job, Jonathan! We may never know all the details of what they knew and how much was forgotten but it's always interesting to see how much they were able to do with the little they had. That should really be a lesson for those who think they can't make a knife without a shop full of the latest tools and supplies....

[Omega]

awesome explanation, if i knew a fraction of what jonathan knows id be well on my way. my goal is to make a midevil sword (stock reduction) but heat treat it myself in a handmade forge (charcoal if i can find a design) and then temper it with the flame, id rather not use a stove, hopefully with some studying and help from the experts here ill be able to make something work

thanks

[tmickley]

Jonathon, have you made any wootz?

[J.Arthur Loose]

Omega,

Personally I think that blades were most likely to be tempered in a simple kiln or on a heated surface, when they were in fact, tempered. ...but that's conjecture.

I'm guessing that any technique you might find the neo-tribalists using is plausible. It's a good question though... I'll put that on the list of things to look out for.

Tracy,

Making wootz would be a little beyond me... Al Pendray and Richard Furrer seem to be the leaders there.

[Jason Cutter]

I just went through some of my sword books and there is never any mention about tempering after hardening. 2 things have occurred to me.

One - a question - with the immense amount of art / knowledge involved in the creation of the Japanese sword, did they not figure out the "tempering colours ?" Or is that something bladesmiths figured out much later / in secret...

Two - Much importance in the making of a sword revolved around the use of the hamon and its shape to ensure that, not if, but when the sword chipped out in heavy use, it would not extend too far up the blade to break it.

This must mean that the steel was somewhat brittle.

I have made some test blades in 1095 / 5160 which are very very much thinner in grind profile than the old swords I have seen and despite the most abuse I can throw at the blade, include chopping through bone and fencing wire etc. I've never been able to significantly chip a blade that badly like I've seen on old Japanese blades (unrestored).

That would confirm to me indirectly that the tempering process could have made a more durable sword ?

I could be talking rubbish here, but just brainstorming. Jason.

[Ray Rogers]

I don't think you are talking rubbish, Jason. In fact, you are re-statng what I have said earlier in the thread. You've done some testing on the subject that I haven't done but it seems to confirm that the ancient Japanese swords might not have exhibited the chipping they did if they had effective tempering.....

[Omega]

you guys all no doubt know much more than i do so if this sounds stupid, sorry. I has watching a show about ancient times a couple of nites ago cant remember the name but in the background i saw some guy with the blacksmith holding a sword over the fire, not in the belly of the fire but in the flame could this have been a process of tempering?

[J.Arthur Loose]

Yup,

That is one really basic way to do it.

You get the blade up to 400-600 degrees F by holding it over the fire and watching the temper colors go from yellow to straw to plum to purple to bright blue to blue-grey. Yellow is really hard and purple / blue are springy. Blue-grey is soft. You still see this method in old blacksmithing & toolmaking books. It isn't too accurate but it is better than not tempering.

It has since become common knowledge that bringing a piece up to tempering temp for about an hour and back down to room temp two or three times converts more of the steel structure than the former process.