3V Sword, Hardness Opinions

O

OTK

Joined
Feb 10, 2010
Messages
389
Howdy,

I am about to start a project that will be a black hole of time, money, and effort: a Japanese style mid length sword made from 3V. We are talking 36" overall, probably 24" blade.

My question for the group is on hardness. Usually these types of cutting instruments would be forged with a springy back and very hard edge. If I use 3V which is very very tough, what hardness should I go for?

Also interested in advice on blade section. There are tons of different sections...I am researching but am not comfortable enough with the proper nomenclature at this time. Just tell me what you like and why.
 
Wish I could help you on that David, but that project sounds awesome......good luck!!
 
I work with a lot of CPM 3V and I would just follow Crucible's data on getting max impact toughness from the heat treat. They say that Hardened 1875°F (1025°C), double tempered 1000°F (540°C)will give you RC 58 and toughness peak impact ratings of 85ft-lbs / 113 joules. Lower the RC any more will reduce the wear resistance to the point that you might as well use S7 and save yourself the time and money grinding 3V.

http://www.crucibleservice.com/eselector/prodbyapp/tooldie/cpm3vt.html

The more important questions are about bevel/edge geometry. "Japanese style mid length sword" is a bit vague. Do you intend to use only the proportions of a katana (curved Japanese sword longer than 23.5")? Are you going for a tradition/reproduction feel? The bevel geometry you choose must be determined by the fusion of style and functional goals you have for the sword.
 
William,

I am going for wakizashi/katana proportions here. Appleseed grind down to zero and not sure how far I'm going to bring it up the flat. Still undecided on a fuller and or a square topped spine. This will certainly not be a traditional build hence the 3V, but I still want to incorporate several traditional elements. Still thinking...lots of details not set at this point.
 
Name the time and place and I'll bring my various OTK blades and we'll destroy yards of fruit and fields of produce!!

OTK said:
Thanks Jay! I may need your help killing some watermelons and such with this thing when I'm done :)
Click to expand...
 
Use the standard HT for 3V, and temper for Rc58. Since you will not be doing yaki-ire, and there will be no hmon, full hardness will be a much stronger sword.
 
58Rc.

3V at 58 is remarkably tough, and the edge-holding will probably surprise you (in a good way).

ETA you may want to contact/look up posts by Daniel Keffeler. He has a lot of experience with this sort of thing, including making swords out of 3V and winning some cutting championships :thumbup:
 
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Hey David! I second James. Definitely google Dan Keffeler and Super Assassin. You'll know he's the man to talk with for 3V in swords after watching some of those videos.
 
OTK said:
William,

I am going for wakizashi/katana proportions here. Appleseed grind down to zero and not sure how far I'm going to bring it up the flat. Still undecided on a fuller and or a square topped spine. This will certainly not be a traditional build hence the 3V, but I still want to incorporate several traditional elements. Still thinking...lots of details not set at this point.
Click to expand...

While an Appleseed/full convex grind gives a blade excellent strength because of the mass left in the blade it may be overkill for a super steel alloy like 3V. 3V is so damn tough you could go much thinner without risking structural failure. A thinner flatter bevel could increase cutting/slicing ability without sacrificing strength. There is also the spring and rebound a sword blade has. Different grinds will make the blade deflect and bend more or less. I have never made a blade bigger than 10" in 3V so I can't speak to the harmonics of such a design.
 
Almost forgot. You can check out Dan Keffeler's work on YouTube to see what his 3v blades can do. Good luck!
 
Make sure you know what yo want to do andget all of the info you can first. YOu are talking about close to $150 just for a 36 x 3 piece of the raw steel if you use the .227/.207 stock
 
OTK
I would be happy to help.
feel free to call me with your ?s

Dan
509 949 2792

OTK said:
Howdy,

I am about to start a project that will be a black hole of time, money, and effort: a Japanese style mid length sword made from 3V. We are talking 36" overall, probably 24" blade.

My question for the group is on hardness. Usually these types of cutting instruments would be forged with a springy back and very hard edge. If I use 3V which is very very tough, what hardness should I go for?

Also interested in advice on blade section. There are tons of different sections...I am researching but am not comfortable enough with the proper nomenclature at this time. Just tell me what you like and why.
Click to expand...
 
Thanks Dan. I'll definitely take you up on that. After looking at some of your work and cutting videos I must say I'm thoroughly impressed. Awesome stuff
 
Dan really is the man. One of the nicest knifemakers I've ever talked with. Has answered every questoin I've ever had and done it happily.
 
Yup, Dan helped me out a lot too with my 3V sword questions. He was incredibly nice, helpful, knowledgeable, etc, and had some good explanations that even made sense to a novice like myself. I posted up about the conversation, which you may or may not find helpful. The short of it is that he's got an awesome HT protocol for 3V swords, and you can just have Peters do it, unless you're looking to do it yourself. I got the impression you could actually just go ahead and take it all the way to 60 or so, and it will still be plenty tough enough.
 
Guys
Thank you all for the assistance. The shop talk forum lives!

It will be a couple of weeks before I get this going but many of my questions have been answered. I will be calling Dan for some additional help. With Stacy's permission I'll keep this one going and show some progress along the way.

Thanks again fellas
 
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