Katana design

Richard338

Richard338

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May 3, 2005
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I have come up with the basic design profile for a katana.
I looked at various parameters on the website http://www.toyamaryu.org/SwordMeasurements.htm and made it fit my piece of 36" x 2" x 3/16" CPM 3V.
I was planning to profile and perhaps distal taper, drill the pin hole and then send for heat treat (do the grind post HT).
Please comment on:
1) do you see any issues with the profile? The blade is 27" and the handle 9". (1" grid mesh in the image)
2) Should I bother to mill in a linear distal taper? Most of the designs on the website have some distal taper, but the width of mine reduces from 1.33 inches at its widest to 0.9" near the tip which will affect the weight distribution and I'm only starting with 3/16" thickness.
3) I realize that the handle is a multicomponent project unto itself, but if I don't want to think too deeply about that yet, can I just drill a pin hole and sort it out later?
Thanks in advance.
dycJBh4.jpg
 
1- I like the profile shape
2- If I could start mine over (36" blade, 50" OAL) I would mill steps into it then connect the dots so to speak, but I started quite a bit thicker as well.
3- Since it's 3V and a PITA to drill even tempered way back with anything but carbide, I would drill an over sized hole where you think your pin will go, like a 5/16" or 3/8" hole, and when it comes back from HT, I would swage in a piece of brass or soft stainless that you can drill right through when you do the handle.

Also, I would bevel it before HT.
 
I have not answer to your questions Richard , I think @stacy is the man for this . But I will add one more question . . . .What about Sori on Katana ? I mean if you already grind Katana to final shape , when quenching Sori will become much bigger ?
Good luck with your new project :thumbsup:
 
Natlek said:
I have not answer to your questions Richard , I think @stacy is the man for this . But I will add one more question . . . .What about Sori on Katana ? I mean if you already grind Katana to final shape , when quenching Sori will become much bigger ?
Good luck with your new project :thumbsup:
Click to expand...
I'm planning to do most of the grind post HT and send it to Peters for HT with the assumption that it won't bend further...
 
It should barely move durring HT. The big bends you see in a traditional katana are the results of a diferential quench of a laminated blade in a super fast quench medium. With a stainless blade beingentirely hardened in air, if there is any sabering from the quench, I doubt it will be visually apparent.
 
Richard338 said:
I'm planning to do most of the grind post HT
Click to expand...
Man that is a lot of cpm 3v to grind post HT! I made that mistake on a wide 5" blade of .20 stock and grinding that sucker took forever, but I have a low budget grinde
 
For a 3V katana:

Profile looks fine. You may want to make the entire width more to start and grind back to the perfect look.

Grind the sori in pre-HT. This isn't going to be hardened by yaki-ire ( where the sori rises in a standard katana).

Pre-grind the basic bevels and taper. The final details can come after HT. Take it to 220 grit pre-HT.

I would leave the machi out until you are done post HT grinding of the bevels and final shaping.

Drill the ana as Kuraki suggested if you need to, or drill it with carbide post-HT ( I would use carbide and do it when fitting the tsuka).

Ask yourself, "Why am I making a 3V katana". Is there some particular attribute that will make it a better katana????
 
Thanks for all the advice everyone.
Stacy, the only reason is that I have a piece of 3V on hand, and have worked with this material quite a bit lately. What material would you have suggested if I didn't have anything yet?
 
Well, I made a 3V wazikashi so I don't see a problem with it :D

I know one thing, it won't wrap around an ice block.
 
If you have it and are familiar with it, 3V is a very tough steel. Just remember to temper for toughness …. not hardness. Rc 58 is plenty hard. While you don't want it to wrap around an ice block, you don't want it to go past it in two pieces either.

Remember that it takes a long HT oven to do a katana. Check with your HT provider if sending I out.

There are two ways to go for the HT:
1) Austenitize at 1950-1975°F with a plate quench and cool to ambient. No cryo. Immediately do a triple temper at 1000°F.
2) Austenitize at 1975°F with a plate quench, do a snap temper at 300°F, then 6+hours cryo. Triple temper at 400°F.
#1 will increase toughness and #2 will increase edge life. Both will come out Rc 58-59. (I would go with the high temper on a katana)

Most katana are great in 1075 low manganese steel.
1084, 1095, W2, and 52100 have also been used successfully. S7 makes the toughest katana ( much tougher than 3V).





This fall I am beginning a research project into Bainitic mixed structures which may be of great value in long thing blades … like katana and wakizashi. The direction of the study will be into bainite/martensite blends and other precipitated carbides.
If we can improve breakage resilience and still keep a good cutting edge it will be interesting to see what comes out of it. Obviously, this isn't the first talk of Bainite in a sword, but we are hoping to get some serious metallurgy out of it. There will be more info over the next year or two on this as things develop.
 
kuraki said:
Well, I made a 3V wazikashi so I don't see a problem with it :D

I know one thing, it won't wrap around an ice block.
Click to expand...
Speaking of ice blocks etc, I looked at some of the Dan Keffeler "super assassin" specs which he makes out of 3V.
They seem to be shorter and wider than any of the traditional designs I have compared with.
I decided to sacrifice some of the 2x4 chopping ability to go with lighter more traditional parameters.
 
Sounds interesting Stacy. Re HT: Peters website says they can handle up to 50". I'll be sure to talk to them about targeting toughness.
 
Richard338 said:
Speaking of ice blocks etc, I looked at some of the Dan Keffeler "super assassin" specs which he makes out of 3V.
They seem to be shorter and wider than any of the traditional designs I have compared with.
I decided to sacrifice some of the 2x4 chopping ability to go with lighter more traditional parameters.
Click to expand...

My waki is more like yours, however it's hollow ground with no distal taper. I ground it before HT because it had a flat land the entire length of the blade for the plates to make contact with, sent it to Bos, came back straight as an arrow.
 
Stacy E. Apelt - Bladesmith said:
If you have it and are familiar with it, 3V is a very tough steel. Just remember to temper for toughness …. not hardness. Rc 58 is plenty hard. While you don't want it to wrap around an ice block, you don't want it to go past it in two pieces either.

Remember that it takes a long HT oven to do a katana. Check with your HT provider if sending I out.



This fall I am beginning a research project into Bainitic mixed structures which may be of great value in long thing blades … like katana and wakizashi. The direction of the study will be into bainite/martensite blends and other precipitated carbides.
If we can improve breakage resilience and still keep a good cutting edge it will be interesting to see what comes out of it. Obviously, this isn't the first talk of Bainite in a sword, but we are hoping to get some serious metallurgy out of it. There will be more info over the next year or two on this as things develop.
Click to expand...


The mythical katana made of Bainite! You will have katana fanboys punching each others lights out over that one!
 
While its nitba hard and fast rule, i like a katana blade to be long enough to just short of touching the ground when held point down in your hand, arm extended down at your side. In my case, about 24".
 
Kevin McGovern said:
While its nitba hard and fast rule, i like a katana blade to be long enough to just short of touching the ground when held point down in your hand, arm extended down at your side. In my case, about 24".
Click to expand...
I was a little concerned about the length since I only have 36" to work with, and many of the designs I looked at are 40" or more, but I think I'll go for it. I can always make another...
 
I would point out that a sword over 24" ( 2 shaku) is a katana. I like a 26-28" katana blade for speed and controllability. I like wakizashi in the 16-18" blade range, and have made some at 14" that are serious slashers.

Much depends on who will be using the swords.
 
I'm glad to hear that the length might be optimal.
Thinking about the bevels, it just registered with me that kuraki mentioned a hollow grind. I'm now thinking about a flat/convex like my chopper. Maybe flat grind leaving 0.03-0.04 before HT, then convex after HT.
 
Stacy E. Apelt - Bladesmith said:
I would point out that a sword over 24" ( 2 shaku) is a katana. I like a 26-28" katana blade for speed and controllability. I like wakizashi in the 16-18" blade range, and have made some at 14" that are serious slashers.

Much depends on who will be using the swords.
Click to expand...

Out of curiosity; is 3/16” the ideal thickness to start out with?
 
I'm interested in Stacy's opinion. According to the website in post #1, many are thicker, but some aren't. Some have significant distal taper. My chopper is 3/16" which is also thinner than most, but it performs pretty well.
 
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