sunobe tip question

Vance C.

Vance C.

Well-Known Member
hey guys, i have a question about the process of making a sunobe, i have been wanting to make a wakisashi for a while, and i finally found a piece of W-2 that i think would be about the perfect size. so anyway, i was searching the good ol' internet for information about the process of making a wakisashi. My questions are if i was to make a sunobe (which i think of as a sword blank, am i correct?)...

would i want to make the sunobe exactly as long as i want the finished blade? because i would think i would want it a little shorter to account for the stretching the metal would endure during forging?

how much growth in width, from blade to spine should i expect from the beveling?

also, how would i want to form the tip of the sunobe?
sunobereversetip.jpg

i found someone who was saying to forge the spine completely straight, like in figure b, but i would think that you would want to do it the opposite way, because the process of forming the tip would cause the tip to bend back too much, and be more work? wouldnt figure A actually end up with a nice straight spine all the way to the tip without much fixing after forging? what do you guys think?

oh and also, would a hamon be tough to achieve on w2 steel?
 
I only know what I have read on this topic.

1. Yes, W2 will produce a very nice hamon.
2. As for the shape of the finished forged blade, yes the spine should be straight. Historically the sori (curvature) was created during the heat treating process.
3. I would want my steel to be close to my desired length. You will have some expansion during the forging process. The length, width, and thickness of your bar and how you draw out the blade will determine which direction you experience the expansion. Given the diagrams you have posted, I would understand that your desire is to start with a bar the same length of your forged blade. You would only want to forge in the bevels and tip. This will cause width and curvature during the forging which you will want to straighten as you go. Your figure A, shows a preforged blank. As you forge in the bevels the metal will expand causeing the blade to curve. As it curves, you can continue to straightn it as you go.

Hope this helps. I'm a dummy but this is what I have understood from my readings.
 
thanks murph, but i hope your not a dummy, because what you said is exactly what i thought! haha i didnt know if there was something that everyone else new, besides me, which happens more often than i would like to admit! but a trick that i just saw on this guy jesus hernandes' website is to draw an outline of the sword in chalk on the floor, so you can reference it as your forging, or draw the tip and dimensions on your anvil in sharpie so you can reference them there too, cool little tips that make life easier! i might do a WIP piece on this project, once i get to it!

and heres a link to jesus hernandes' tutorial for a wakisashi-
http://www.jhbladesmith.com/en/tutorials/the-making-of/sanmai-cable-wakizashi.html
 
I'm familiar with his work but not very knowledgeable. I have heard really goods things about him.
 
I know Jesus very well ,he is a top smith , he makes all his own tamahagane . murph is correct forge in bevels ( shinogi) along with kissaki (point) and boshi ( blades tip edge ) of the 5 great japanese smithing schools called the Gokaden ( 5 traditions ) some started at the tip some started with the tang . you must also forge and cut in the hamachi and munemache where the habaki fits before hardening , or it real tough to grind them with out losing some hardness . Make sure the claying is even thickness and design on both sides as much as possible . Other wise the sword will warp or bend during quench . Unlike knives which you can put clay all over the place without much problem , but with swords because of length claying is critical , as I have found out many times. I would like to see your WIP it would be nice . Bubba
 
Vance C. said:
My questions are if i was to make a sunobe (which i think of as a sword blank, am i correct?)...
Yes, you can think of the sunobe as the "sword blank". Others refer to it as a preform.
The forging process is done in two stages- preform and bevels. The preform (sunobe) stage will set the shape and preliminary dimensions. The final dimensions will be set in the second stage when forging the bevels.
I do not know the literal translation, but the main idea is that the sunobe is the primary shape without bevels. Keep in mind that the sunobe includes the taper, both in thickness and width.

would i want to make the sunobe exactly as long as i want the finished blade? because i would think i would want it a little shorter to account for the stretching the metal would endure during forging?
As a very general rule of thumb, the sunobe would be approximately 90% of final length. Or, looking at it another way, we could say the final length is 110% of the sunobe.
Some people do well by sticking with figures. For example, for a final nagasa (blade length) of 18", make the sunobe 17". Note that this does not follow the 90/110 rule. Just goes to show you nothing is set in stone.
The reason these "rules of thumb" are not set in stone is due to the fact that the amounts of taper (both in width and thickness) may vary from one sword to the next.

how much growth in width, from blade to spine should i expect from the beveling?
I believe allowing for 1/4" growth in width should get you in the ballpark. But this is based upon the dimensions of stock you use, and also your taper; most people start with a 1" wide x 1/4" thick bar and get approximately 1/4" extra width when going from stage 1 (sunobe) to stage 2 (set bevels).
So if you follow that as a starting point, if you desire a final width of 1-1/8" (at machi), you would need "about" a 7/8" sunobe width at the same location.
Again, this is simply a generality. Forging methods, initial stock thickness, degrees of taper, desired edge thickness, amount of niku, etc. will all be final determinants.
This is something you have to find out for yourself, and it will never be exactly the same from blade to blade.

also, how would i want to form the tip of the sunobe?
When making the sunobe, forge the kissaki in the same general shape as you would want it in finished form. It doesn't have to be exact, as much will be corrected when setting the bevels, and also in final grinding and polishing. But it needs to be close to shape.

sunobereversetip.jpg

i found someone who was saying to forge the spine completely straight, like in figure b, but i would think that you would want to do it the opposite way, because the process of forming the tip would cause the tip to bend back too much, and be more work? wouldnt figure A actually end up with a nice straight spine all the way to the tip without much fixing after forging? what do you guys think?
I do not fully comprehend image A; it appears to be a reversed tip.
Image B is what you want.
Are you attempting to overcompensate for sori during HT? If so, don't worry about it. That's putting the cart before the horse, because at this stage you do not know for sure exactly how much sori you're going to obtain.
Simply make the spine straight from the machi all the way to the kissaki. Remember, minor adjustments are always made during grinding/polishing.

oh and also, would a hamon be tough to achieve on w2 steel?
I have never used W-2, so I cannot say from personal experience. But many others have had good results with it.
Steel choice most certainly has an effect on the hamon, but also keep in mind that HT procedures are just as important in obtaining the final outcome.
Click to expand...

Hope this helps a little.
Remember, its a 2-stage forging process; sunobe to set the shape, and then the bevels. Think of the sunobe as the foundation which affects everything else after. Personally, I believe shaping the sunobe demands more attention than forging the bevels, simply because the tapers are forged while making the sunobe.

For more information, see if you can get in contact with Jesus Hernandez or Walter Sorrells. They are both very accomplished smiths who also happen to be practitioners, meaning they actually use swords in the various Japanese sword arts.
Another person you may seek guidance from is Bubba-san, a member of this forum.

Good Luck,
Rob
 
rob45 said:
For more information, see if you can get in contact with Jesus Hernandez or Walter Sorrells.
Another person you may seek guidance from is Bubba-san, a member of this forum.

Good Luck,
Rob
Click to expand...

Bubb-san, sorry about the late note- I noticed after I posted that you had already responded to the thread.
Had to leave the computer to take care of something outside while in the middle of the post this morning.

Thanks,
Rob
 
I do not fully comprehend image A; it appears to be a reversed tip.
Image B is what you want.
Click to expand...
rob45- thanks for the help, since i have only done knives, i am used to forging the tip down, like in image a, because when i bevel the cutting edge, the spine will straighten, but making a sword i would just make small adjustments as i am forging on a sunobe modeled after image b?

so if im making a wakisashi thats just about 24 inches overall, 1.25 inches wide at the tsube with a slight taper to the kissaki, i would start with a 21.5 inch long sunobe that is about one inch wide at the soon-to-be tsube, with a little bit of a taper to the kissaki...yeah?
 
Vance C. said:
rob45- thanks for the help, since i have only done knives, i am used to forging the tip down, like in image a, because when i bevel the cutting edge, the spine will straighten, but making a sword i would just make small adjustments as i am forging on a sunobe modeled after image b?

Exactly.
I see what you're saying now. That goes back to putting the cart before the horse- if you forge in the "upside-down tip", as in image A, then you MUST achieve a certain degree of curvature in later operations. The problem with that approach is that you have no idea if you can get enough curvature in those later operations to overcome the reverse you intentionally put in.
You have not mentioned whether you are doing hira-zukuri or shinogi-zukuri. Since you seem to have interest in a wakizashi, I am going under the assumption that you are wanting to do a hira-zukuri.
If you were doing a shinogi-zukuri, THEN it would be prudent to put in a slight "spear point" (meaning it drops to a point from both top and bottom, only not as severe a drop from top) when forging the sunobe. But that is because the kissaki on a shinogi-zukuri is completely different, geometrically speaking. Due to the way the kissaki is shaped, in that instance the slight "drop" would be an asset to the sunobe, as it would allow easier shaping when it comes time to set the bevels.
Going under the assumption that you will be using a differential HT (aka clay hardening) with water as the quenchant, the sori will occur naturally.
Again, assuming you are doing hira-zukuri, your best option is to keep the back (spine, top, whatever everyone wants to call it) of the blade straight.
As you may already know, whenever you begin to forge the bevels, the blade will want to curve- simply turn the blade edge up and lightly tap it back straight.


so if im making a wakisashi thats just about 24 inches overall, 1.25 inches wide at the tsube with a slight taper to the kissaki, i would start with a 21.5 inch long sunobe that is about one inch wide at the soon-to-be tsube, with a little bit of a taper to the kissaki...yeah?

You mentioned "24 inches overall", so I assume you are implying maybe 18" nagasa (blade length as measured from machi to kissaki) with a 6" nakago (tang)?
Don't forget the thickness of your starting stock when making these types of estimations. Thin stock combined with a short starting length will result in a toothpick-thin blade. On the other end of the spectrum, starting with stock that is too thick will not only create more work at the anvil setting the taper in thickness, but can also easily lead to a "tip-heavy" blade.
The thickness of your starting stock is also directly linked to your desired blade width. Of course, you can have any width you desire, but, traditionally speaking, the width needs to be proportional to length for things to "look right".

For a final nagasa of around 18", I would start with 1/4" thick stock.
When making the sunobe, set the initial width at machi (motohaba?) around 7/8", tapering to maybe 5/8" width until you begin to reach the kissaki. A few inches from the very tip it then starts the sharp dive to form the kissaka. This should give you about 1-1/8", give or take a little, final width at the machi. Put the length of the sunobe at about 17" to be on the safe side.
Remember the "rules of thumb". Better to err on too long rather than too short - you know, the old adage "easier to take off than put back on". If things don't look right to you, you can go back and correct it providing you have enough material to work with. If there's not enough material, you're stuck with a blade that is either too short, too thin, too narrow, or all the above.
Click to expand...

These are guidelines based on my experience, which is still very limited. The Japanese blades have held my interest for many years, mainly due to the fact that I have a friend who both collects and uses them. But that does not make me an expert at this stuff. I've made one tanto and three wakizashis, so I've got a long way to go.

I really wish my computer skills were more advanced, so as to have the ability to post drawings, pics, etc. to make it all seem more clear and less long-winded. But I don't even own a digital camera, let alone know how to use one!
Still, it would be nice to show you a pic of my first wak; it looked more like a distorted scimitar sword than a Japanese short sword!:biggrin:
Knowledge is wonderful, but that project showed me that forging skills are developed through experience.


One other thing, since we're talking about keeping the back straight. Whenever you shape the nakago, it also needs to be tapered and beveled for purposes of the mountings. As you shape the nakago, it's more than likely OK to leave that slight curve in there, but only on the nakago.
The reason for this is due to the method of heat treatment. Sori will be created in the blade during the quench, but the nakago will not be subject to that effect. Having a very slight pre-established curve in the nakago will be beneficial to the overall "flow" of the curvature.

Good Luck,
Rob
 
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thanks rob, that information does help a whole lot, with or without pictures! the only reason i had a picture is because i found it somewhere else, and copied it onto here! I am sure i will learn what all the japanese terms for the parts of the sword, because i have a feeling ill be asking more questions as i go! i have been interested in making one of these swords for a while, but the only kind of sword i have already made was a roman gladius, which wasnt the prettiest thing i have seen, but it was a fun project, about 2 years ago. since i have been studying more metallurgy and techniques and building my skill. hopefully i wont embarrass myself when i finally post a "making of" of this project! hahaha but you really have been exceptionally helpful and thorough in your reasoning.

i think one of the next questions i have is where to find information on how to do the wrapping on the handle, i know i wont be able to do this step until i actually have the sword pretty much finished, but i would like to practice, and use it on other things, playing with cordage is great fun! i even learned how to make bull whips out of paracord!
 
I'll try to find the website, if it still exists where they describe the ito wrapping. Last time I was on the page it was posted that the page was being removed. If I can't find it, I'll try to find the copy of the instructions I printed and post a copy of them.

EDIT: Here's the link: http://pages.prodigy.net/tlbuck/tsuka/tsuka.htm
Be sure to print out the information. I tried saving it to a file, but for one reason or another it wouldn't allow me. The page will be deleted on June 1st.
 
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This what it should look like after initial forging but, remember of the 5 great traditions they all forged it a little different . The sunobe should be straight before quench . However if you are oil quenching you must forge in the sori , because oil does not make the blade curve much at all . If you use water then the sunobe must be straight . it should look something like this. Bubba

PS here is link to bucks new site , but it looks like he removed the instruction page showing how wrapping is done . http://www.tsukamaki.net/#

W-2 is great if it is low manganese . Aldo has some real nice stuff in stock . He also has some 1075 low mang. that makes an outstanding Hamon . 1075 is very close to tamahagane in some respects . walter uses it a lot . good luck
 
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thanks bubba san, i dont honestly know if it is low manganese, its a giant file that i picked up at an estate sale, i was going to draw it out, its 16"x .25"x 1.375" so i thought its almost the perfect size! but i dont know if it has a lot of manganese in it. i actually do also have some 1075 i got from admiral steel thats about the same dimension as the file, do you know if admiral steel's produtcs have a lot of manganese?
 
Vance C. said:
since i have been studying more metallurgy and techniques and building my skill. hopefully i wont embarrass myself when i finally post a "making of" of this project!
Click to expand...


Don't worry about embarrassing yourself.

These types of projects require considerable investment in both knowledge and time.
One large advantage we have going for us is that we can use modern steels, which greatly speeds up the process. We also have modern methods and equipment at our disposal.

The point is, even with those advantages, you are attempting a project that many will not. Mistakes will be made, but around here the saying goes, "if you don't make any mistakes, you're not learning right".

With today's exchange of information, we have the huge benefit of learning from the mistakes of others. This greatly shortens the learning curve.
But we still need to compare it to learning how to ride a bike. Someone else can tell a child how to ride; they can even show them. But chances are, the child will still fall over. The child gets hurt, embarrassed, or both.
Now, the real question- does the child get back on the bike? If he doesn't, he will never learn how to ride.

This stuff isn't easy, but it's very rewarding.
Something I say to others after a rough day at work- "If it were that easy, everyone would be doing it."


Rob
 
Vance C. said:
I am sure i will learn what all the japanese terms for the parts of the sword, because i have a feeling ill be asking more questions as i go!
Click to expand...

Questions are good; I still have a million questions myself!

Learning the terminology certainly makes things easier, as most of these discussions will involve it.
It' not like you have to learn the entire Japanese language, although further study is fine if that's what you desire.
But it's fairly easy to learn the basics that surround your area of interest.

There is a reason for this, and, contrary to popular belief, it's not to "boast your knowledge".
There are many times when one or two Japanese words can take several words, an entire sentence, or even more in another language before the idea is effectively communicated.
This problem can exist between several languages, not just Japanese and English.


An internet search can get you started.
Enter phrases such as "Japanese sword terminology", "samurai sword", "katana", etc. and you'll be flooded with many different sites.
Some good, some not so good. You'll soon learn to separate the wheat from the chaff. But most of them are accurate enough to get you started on the basics.

I just punched in a search myself; here's a couple:
http://www.samuraisword.com/glossary/index.htm
http://home.earthlink.net/~steinrl/glossary.htm
 
According to the craft of the japanese sword the sunobe should be about 90 percent of the blade length. the width and thickness of the sunobe adds up to the final width of the blade, and about 10% of the length in your case an inch wide and 1/4 inch thick for a finished blade that is 1 1/4 inches wide. the sunobe is tapered about 30% in both thickness and width and the Shape of the sunobe is as in your #2 illistration. http://books.google.com/books?id=CGZPvLkmP3IC&lpg=PA81&ots=NRLEPX0UuO&dq=sunobe%20shapes&pg=PA81#v=onepage&q=sunobe%20shapes&f=false
 
Vance C. said:
thanks bubba san, i dont honestly know if it is low manganese, its a giant file that i picked up at an estate sale, i was going to draw it out, its 16"x .25"x 1.375" so i thought its almost the perfect size! but i dont know if it has a lot of manganese in it. i actually do also have some 1075 i got from admiral steel thats about the same dimension as the file, do you know if admiral steel's produtcs have a lot of manganese?
Click to expand...

I agree with bubba-san on this; you want low amounts of manganese.

As to using a large file, keep in mind that you are about to embark on a sword project, which is considered by many to be the pinnacle of knifemaking.
Compared to making a knife, everything about a sword of any type is magnified many times over. This includes details of heat treating, which makes or breaks the entire project.
Much discussion has been made in several threads on this forum and others regarding the use of unknown steel.
Here is but one:
http://knifedogs.com/showthread.php?17770-Salvaging-Steel

Regarding the manganese content, it helps to know the effects of it and why we would want it or not. Please understand that I still have a lot to learn, but this is what I have gleaned thus far (primarily from a person employed by AK Steel in nearby Rockport, IN).

Nearly all modern mill steel will include manganese in varying amounts. The reason for this is due to the benefits it provides during the steel-making process.
From what I understand, it is used to deoxidize and degas the steel during the melting process, and can counteract the effects of sulfur, which is considered an impurity nearly always present.
A side benefit is that manganese lowers the quench temperatures, allowing the steel to more easily convert into martensite (the "hard" form).

So, manganese sounds great, except for the fact that we have a unique application. We are using a differential HT to intentionally create a blade with a hard edge and soft spine. As you may already know, this is what creates the hamon we're all after.
To accomplish this effect (hard edge/soft spine, resulting in a hamon), we need a steel that is MORE DIFFICULT to convert into martensite.
Remember, the more manganese in the alloy, the easier it is to harden the steel. The easier that is, the more problems will occur with a differential HT.

Using conventional methods, here are a few results of too much manganese:
A spine that is "not soft enough".
A "washy" hamon.
Or sometimes even no hamon at all.

All of the above is not to say that you cannot work around manganese, because many people have "done what could not be done". But using those alloys will demand much "adjustment" in the overall heat treating process.


Rob
 
so i just looked it up, and the 1075 from admiral steel has a manganese content of .40 to .90, would that be considered high?
 
Vance C. said:
so i just looked it up, and the 1075 from admiral steel has a manganese content of .40 to .90, would that be considered high?
Click to expand...

Why can't they give a closer figure than that? A margin that wide would have me calling them.

I cannot say for sure how high would be acceptable. This is a case where you need to find somebody that has differentially heat-treated many different blades with varying known amounts of Mn.

I do know that I have achieved great results with some W1 that supposedly had .4% manganese. Based only on that experience, that makes me want to keep it below .5%. But then again, keep in mind that I personally have not tried anything higher. I'm sure that time will eventually come.

Were I in your shoes, here would be my method of approach:
1. Contact Admiral and find out what's up with the "estimations". I can understand a couple of points, but five?
2. Scour the internet for answers to the question "how much Mn is too much?" Check all the various forums, solicit information from people who have a lot of experience using modern steels with a differential HT.
Maybe somebody reading this could chime in. For that matter, Kevin Cashen over in the heat treating forum may be able to provide some insight.
3. Consider bubba-san's hint about Aldo as a supplier of higher-quality 1075. For the amount of time you're going to have invested in this project, the steel is very cheap by comparison.
http://njsteelbaron.com/index.php/store?page=shop.product_details&flypage=flypage.tpl&product_id=6535&category_id=9
4. You are wondering about both your file and the Admiral piece. Nothing beats actual results, so why not take some of that and use your same processes to do a much smaller project? There's nothing wrong with a small tanto, skinner, etc. Perhaps this would allow you to determine if your methods are compatible with that particular steel before investing all the time into the much larger sword project.
 
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