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High-Performance Blades Sharing ideas for getting the most out of our steel. |
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#1
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"Battle ready blades"
Hello I m just making me viking longknife and starting on viking sword.
These should be blunt, but close to real weapon in terms of weight. Most local makers use 5160 series local makeup steel for this, but as people use these swords for things you ?d never do with sharp blade, very often these swords are too overbuilt. Typical hardening goes around RC 50. I have S1 for blades. Its not AISI S1, but old Poldi steel Tenax H shockresistant. Its somehow legendary and hard to get as its not made anymore. Also quite pricey. This is chemical makeup of my steel C 0.5 - 0.6 W 1.7-2.20 Cr 0.9 -1.2 Si 0.8-1.2 I have seen recently short knife made out of this and it chopped nails and bolts without scratch to edge. Anyway I have precut the blank for longknife (its really battle knife, not single edged sword). I have 8 mm next to tang. I was thinking that distall taper to around 4 mm at tip will be just about. I also think about grinding the blade hollow as on some of viking single edged swords to improve handling and get the weight down. But the spine of these big knives was often so thick. There is recent found of such knife near of my house and it has 10 mm spine (next to handle tang) with some distal tapper. Now the real question comes. How thick the edge shall be to survive beating at whats virtually lots of junk metal in RC 50. Can you reccomend me heat treating for this steel so I can get around RC 58 and maximum toughness? I need temps in C. I have 5mm stuff for the sword. Again I thought bout having distal from 5 mm to 3 mm at tip, with blade width 64 mm at crossguard and 40 at tip. So. How thick to leave it and what hardness is advisable with this material? I have just recently ground big bowie from this steel, but I sent it for HT to some company. I must admit I feel uneasy about it as I dont have things under controll and industrial HT companies have little understanding to swords. Thanks for advices. Jaro |
#2
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Jaro, as this is an international forum it's a good idea to tell us where you live ! Czech Republic ?? Is there any way to get information on this steel from a library perhaps in a university ?
My educated guess for heat treatment would be harden at 900-970 C, oil quench, temper about 260 C. |
#3
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Well, yes its Czech. Its relativelly easy to get info on that steel, but opinions differ strongly what to do for HT. It can be ocasionally found in prybars and power hammer bits.
Then its hardened to some RC 50 with high toughness. Just about every company around knows how to do this, but If I send them sword blank and demand this and this then its a lottery and I m not very keen on wasting so much work on bad HT. One of my knifemaking friends told me that when taken above austenitic temp and letting air cool without quench, it does arrive at 58 RC preciselly and there is no need to temper anymore. But that was for knife, not sword. Another man who is machinist and makes tooling whole live told me that some HT companies didnt wanted to deal with this steel "since it requires higher temps". - Which might or might not be true, I just suspect that it just needs more precise handling that most common steels used around - such as local equivallents of W1. Also, this steel is not supposed to be wear resistant, but it chews drill bits nicelly even when annealed and in 1 year forresters test concerning butchering the game fared only very slightly worse than D2 when it comes to frequence of the sharpening. I have found this Hardening 870 – 920 C Tempering 150 – 250 C But its somehow mildly confusing. Im not knifemaker by trade and its first time I m working with this material. Jaro |
#4
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Difficulty in drilling is due to the fact that the W carbides are very wear resistant !
ALWAYS temper after hardening ! While you might aim for 58 HRc for a knife , a sword should be somewhat softer[and tougher] as it is an impact weapon. 52-55 HRc would be better. If you can find a tempering curve that will tell you how to get that hardness. |
#5
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Looking through some references on-line I would say what you have does come out pretty close to AISI S1. I would take it up to non-magnetic and let it soak for a bit (without a calibrated and controled oven the temperature before quench doesn't mean much) and quench in oil (the oil should be warm but not over 160 degrees F). The tempering data that I found is as follows
Degrees F / Rockwell hardness 400 / 56.5 500 / 54 600 / 53 700 / 52 800 / 50 As you can see, you will need something more than the kitchen oven to bring the hardness down to 50 Rockwell. I'd suggest three cycles of two hours each allowing the steel to return to ambient temperature between cycles. The reason for cycling like that is to allow the retained austinite to convert to martinsite which is then tempered on the next cycle. Doug Lester __________________ If you're not making mistakes then you're not trying hard enough |
#6
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Thanks. So how do the hardness/toughness curves go on 5160 and S1 in comparison?
Jaro |
#7
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Result:
Jaro |
#8
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Same steel, different knife. This is sharp 49 cm long and 8 mm thick at spine.
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#9
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Now you can chop trees down with that !!
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#10
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Interesting grind! Sort of like Mr. Moran used to do in the early stages of a knife, using a 8 - 10 inch wheel. He'd hover himself way over the top of the blade and wheel. I haven't tried it but it looks like you might have with thi knife. Did you form the plunge cut with a small wheel? I agree with Mete, go find a big tree )
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#11
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Your analysis is correct.
Since I m not knifemaker, I used this contraption to grind the blade I only tried light chopping since there was no handle yet after grind. This is with cca 10-15 cm short swing. I made it for my buddy here, he is arm wrestler. Believe me, it does not look so big when he is holding it. But there are drawbacks - Its very heavy. With 800 gram it has this lovely feeling of the brick in the hand, altough its relativelly well ballanced. (He says he likes it.) I think its too thick. Knife of half the weight can be made to cut with the same performance. Also the company I send it to HT did only a so-so job. I think it could be better. On the positive side the edge wont get stuck in wood and it really goes in, so the edge geometry is not all that bad. Jaro |
#12
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Congrats!Looks swell.Cool little grinder, it just goes to show tools arent the most important part of knife making,but please start wearing eye protection while grinding.
__________________ N'T McAhron Sqwaukin Vulture Verrinder "to create is to make art" TREMBLING EARTH KNIFE WORKS |
#13
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O.K. I will I promise!
Jaro |
#14
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Awsome!!!
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blade, knife, knife making, knives |
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