Donnerstag, 14. Januar 2016

Sica and the 440C mishap

 Also on the bench these days are two obsessions of mine... the lower knife in the pic is another experiment with handle ergonomics and blade layout. I had one strange billet still lying around from the days of Matthias Zwissler, and it seemed to be monster Damascus. Okay, I looked forward to it and forged it out into a seax blade, a small billet and this bush design. When forging it, it proved a bastard with just a very small forging temperature window, and blimey was I glad to have a power hammer at hand! So, I looked forward even more to it, and normalized it for drilling and grinding, and did all the usual stuff I do to carbon steels, but-bummer, it did not work. I dulled my cobalt drills, and even my glass drill I normally use for weekend project blades that are already tempered did not move any material at all. So, back to the drawing board, some more annealing, and when I was at it I thought... well, why not punch it through, and with a bit of help by Moritz, hot-punched the holes, did some annealing (5 hours at about 600 ° C or so), until I could work it with a file all over. Then I ground it into shape and gave it a selective quench in pre-heated lard. Off to the polish then. It worked down my water stone, so I used the diamond strop instead. And grinding. And grinding. And when I was done grinding I did some more grinding with little effect. I was becoming eager and wanted to do a quick etch with salt, vinegar and citric acid. No pattern showed. Okay, I said, give it a coffee... no effect. But it was only after I had left it in 24 hours (normally ten minutes or so...) that I realized that this was no carbon steel. Since the only stainless steel Matthias had ever used was 440C, I guess the knife is 440C. Spark analysis shows a carbon content of 07-1,00% or so when compared to spring and file steel. First stainless steel for me, and I am surprised and pleased to see it gets a fine edge and seems sturdy enough to take a beating. Might be more stainless blades then for me in the future... I plan to fit some striped maple or elk horn handle with fibre liners and mosaic pins to it and give the blade some engraving and polishing. We´ll see.

The next one  is a very interesting style of historical knife. I found a historical piece of crucible steel in the woods that once seemed to have been a cold chisel, and it has a carbon content of about 0,7-1,00%, too, when compared to file steel and spring steel. I have always called this blade shape a "Kopis", but morphologically it is more correct to call it a Sica, a knife made famous by Dacian people in the iron age. There is a whole world of variations, the one thing in common is that they offer one sickle-like edge (the word "sickle" derives from Roman "sicula"-tiny sica). The earliest examples from the Hallstatt period (from 890BC) are often strongly curved with little or no straight tip section. Later on the tip section was becoming more pronounced for some examples resulting in a shape more like the blade I forged. The integral bolster is not authentic, at least I do not know any examples of this, and this would be logical if you keep in mind how precious iron, and more so, high-carbon iron of good quality had been at the time.

Look at these excellent articles (in Romanian language):

It is a most fascinating type of knife and I plan to do more of that stuff... watch this place!

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