Ronin Katana

I appreciate the compliments, but there are so many guys who know so much more than me on this site, that it seems odd to be called Professor. I worry it is disrespectful to them to accept such a compliment.

To explain my previous post since you seem to be interested in this:

Chromium and manganese are added to steel to increase hardenability. Manganese is absolutely needed as it ties up impurities as well, while chromium is optional. The max hardness does not change, but the depth of hardening in the quench improves, as chromium increases the time the steel has to convert to martensite, the hardened state of steel. The difference is quite significant, such as 0.5s to 5.0s with 1-1.5% chromium. (The time it takes to get from the heated state, about 1450f to 1550f, depending on the steel, to the martensite forming temperatures, several hundred degrees cooler.) 13% chromium is the point steel becomes stainless, so we are talking about much smaller amounts. This slowing allows the steel to fully through harden, while simpler carbon steels without chromium can partially harden. This is what causes the hamon. What you are seeing is the transition between the martensite at the edge, and the pearlite higher on the blade (Which forms when the steel cools too slowly to make martensite). Manganese increases the depth of hardening as well. Most carbon steels use about 0.8% manganese, which washes out the transition definition. Steels under 0.4% manganese show the best hamons. My 15n20 is 0.35% manganese, and doesn't have the chromium common in this steel, so it does develop a pretty nice hamon. W2, 1075, and 1095 all have about 0.3% manganese, which is why they are chosen for hamons.
 
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So in this modern era of swordmaking, is DH just purely for looks/aesthetics? Should TH blades be preferred for toughness? I assume the DH allows for a better edge-holding then the TH though, correct? Stainless is good because it doesn't rust as easily, but is difficult to hold a good edge, correct? And if manganese is roughly equivalent to chromium as far as hardening is concerned, I don't see why anyone would use chromium at all. Excellent info there, Willie. Thanks, my man.
 
DH was a way to make up for the inclusions and impurities in crucible steel. It allowed flex, rather than breaking at the inclusions. In modern times, it is purely an esthetic embellishment. A TH blade is superior assuming the heat treat was done well. Tempered martensite is stronger than pearlite. You can do differential tempering as well, but it doesn't look like a hamon.

Stainless doesn't rust, and actually holds an edge longer due to the chromium carbides it naturally produces in heat treat. The Chromium carbides are very hard, but large, which is why older stainless blades always have a toothy feel, like microserrations. They wear slowly. A lot of science has gone into powdered metallurgy, such as the CPM steels to offset this. (CPM 154, CPM S35VN) AEB-L is the exception to the traditional stainless steels as it has just enough Chromium to make it stainless, but not enough left over to make the large carbides. This is what modern razor blades are made out of. The manganese doesn't slow the cooling nearly as much as the chromium, and doesn't increase toughness or add wear resistance. With Chromium it comes at the cost of fine edge ability, but as I said with modern steels that is less of an issue.

All of this is tradeoffs. Steels like W2, 52100, O1, 15N20, L6, are all a different mix of these elements and others such as vanadium and tungsten in small amounts to fine tune the properties of steel.

Check out this thread on AEB-L. http://www.bladeforums.com/forums/s...ness-in-larger-blades?highlight=aeb-l+chopper How much more does one need? After this thread, I bought a bunch of AEB-L for some skinners. Its great stuff and gets scary sharp, like 52100, or W2.

Edit to add: A blade with a hamon also shows the steel was not overheated in heat treat. If you get the steel too hot, the hamon won't form as it takes too long to get to the martensite start temp. Overheating the steel causes grain growth, migration of alloying elements into grain boundaries, and the steel is more brittle, with less ability to get a keen edge. It shows the superior control the smith has over the process. Look up guys like Don Fogg, Nick Wheeler, and Don Hanson III to see the amazing results these guys get.
 
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Interesting and informative thread. This is the first time I have seen or heard of it, but apparently it's been around since the 20's. Go figure. I know you have stated previously that swords aren't really your forte, but as far as the OP is concerned(myself included), what are your thoughts, if any, on Ronin Katana? More specifically their Dojo Pro line? They seem to be a really great offering. Good reviews. They use a 1060 TH steel for their Dojo Pro line. I have heard various opinions on this. What is your personal opinion? Assuming all have good and proper heat treatment, are 1566 and 9260 that much superior to 1060? Thanks a lot Willie!
 
You touched on 1560 and 9260, but I'm not sure if you knew that the Ronin Katana Dojo Pro's were 1060 TH. I'm just curious of a comparison here.
 
A properly heat treated 1060 blade will work very well too. It will naturally differentially harden a bit as it is less than 0.77% carbon. Some pearlite has to form as there isn't enough carbon to mix with all the iron. It forms a different type of martensite than the over 0.77% carbon steels. The martensite concentrates at the narrow part of a wedge shaped object over 3/16" thick (I am trying to figure out why- Its cool that it does, but I need to know why now.) The alloying elements in the 5160 and 9260 make heat treatment easier, but properly heat treated 1060 is a great steel for a large blade. It is naturally tough (at least tough enough- example 52100 is the steel your car's ball bearings are made of- those 4 small bearings hold your whole car up for 40,000miles or more! Do we really need this in a knife or sword?) The 9260 and 5160 (all else being equal) have a bit better toughness and flexibility. They MIGHT hold an edge a bit better. If you were a professional bamboo mat cutter, cutting for 8h/d, 5d/week, the added elements might come in handy. For occasional playing around? You probably won't know the difference.
 
Willie71 said:
A properly heat treated 1060 blade will work very well too. It will naturally differentially harden a bit as it is less than 0.77% carbon. Some pearlite has to form as there isn't enough carbon to mix with all the iron. It forms a different type of martensite than the over 0.77% carbon steels. The martensite concentrates at the narrow part of a wedge shaped object over 3/16" thick (I am trying to figure out why- Its cool that it does, but I need to know why now.) The alloying elements in the 5160 and 9260 make heat treatment easier, but properly heat treated 1060 is a great steel for a large blade. It is naturally tough (at least tough enough- example 52100 is the steel your car's ball bearings are made of- those 4 small bearings hold your whole car up for 40,000miles or more! Do we really need this in a knife or sword?) The 9260 and 5160 (all else being equal) have a bit better toughness and flexibility. They MIGHT hold an edge a bit better. If you were a professional bamboo mat cutter, cutting for 8h/d, 5d/week, the added elements might come in handy. For occasional playing around? You probably won't know the difference.
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Informative as ALWAYS! There was a thread on the SBG forum from the RK manufacturer about the hamon activity you mentioned. While not all the time able to see clearly with the naked eye, their DP katanas are known to have a "ghost hamon." It's an older thread, and it got a bit heated on there, but it is informative as well. I don't think anyone knows "why" it is taking place, but it does. One sword maker in particular stated that just about every blade has a hamon, if you know what to look for. He said it was part of the heat treat process. He even gave examples of some historical EUROPEAN blades with hamons! So I guess certain elements, like your manganese, makes this hamon activity more clearly defined.

I plan on making a purchase sometime next month most likely. I definitely have time to research. Just trying to gain as much knowledge as I can so I can make the best decision for me. You are the SHIT Willie! Thanks a lot for letting me pick your brain a bit. Very helpful, intelligent, and informative.
 
I just learned about the effect of the wedge on the martensite/pearlite a few days ago. It's completely different in a cylindrical object- the surface hardens to martensite while the center is pearlite. 1060 has been used in farm plows and discs for years, being dragged through miles upon miles of dirt and rocks. They don't get replaced often either. in recent years 9260 has become popular as it is tougher and easier to heat treat consistently, but 1060 has been in use for many decades. We spend too much time trying to get a "better" steel, when what we need to do is maximize the steel we have.

Re: the ghost hamon, guys like Verhoeven and Cashen can explain it, I'm sure, but I don't know enough yet. What I do know is there is no such thing as pure martensite in a blade. 10-30% will be other structures, such as cementite, pearlite, retained austentite, unless you have an extremely high tech lab with unobtainium type heat treat equipment. If it is a simple steel (Fe, C, Mn only- 10XX steels) over 1/4" thick, there will be some differential hardening in nearly 100% of the blades. Getting a full conversion without additional alloying elements requires such a shock producing quench, the blade is almost guaranteed to crack due to the extreme transformation the crystal structure experiences.
 
Scotty2Hotty said:
Informative as ALWAYS! There was a thread on the SBG forum from the RK manufacturer about the hamon activity you mentioned. While not all the time able to see clearly with the naked eye, their DP katanas are known to have a "ghost hamon." It's an older thread, and it got a bit heated on there, but it is informative as well. I don't think anyone knows "why" it is taking place, but it does. One sword maker in particular stated that just about every blade has a hamon, if you know what to look for. He said it was part of the heat treat process. He even gave examples of some historical EUROPEAN blades with hamons! So I guess certain elements, like your manganese, makes this hamon activity more clearly defined.
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This isn't true. If it's not differentially tempered, there's no hamon. You're not likely to see a hamon out of through-tempered 3V, for instance, although you might in a 10-series carbon steel for the reasons listed by Willie. More on this in a moment. As far as why hamons appear, it's because the difference in the temper between the edge and the spine thanks to the clay (or satanite in modern blades, often), causes different crystalline matrices. Because they are oriented differently and are different sizes, they'll appear different in the right light and with the appropriate level of polishing, or with an acid etch. I could go into depth on the optical physics behind it, but I don't think anyone really wants to see formulae here. It's basically the same reason that you can see different patterns in carbon fiber because the fibers are oriented in different ways, just on a much more microscopic scale.

As Willie says, the heat treat is the most important aspect, and worrying about 9260 vs 5160 vs 1060 etc, especially if we primarily care about toughness, is counter productive if we don't know how good the heat treat is.

A few more things to consider: we differentially harden simple carbon steels because we need a hard edge that will stay sharp, but we need a softer spine because in a simple carbon steel, the harder it gets, the more brittle it gets. Steel is really made up of microscopic crystals, and the heat treat determines the shape (that's what we're talking about with regards to martensite, pearlite, austenite, etc). The heat treat also determines the distance the crystals are apart from each other. The closer together they have, the less movement they can make, as you can imagine. And, similarly, if a crystal gets out of place far enough, it's not going to be able to slip back into its spot. A simpler analogy would be a pattern of hexagons fit together. When you torque the pattern enough, the hexagons aren't going to fit together, and the pattern will fall apart. The softer heat treat provides more flexibility and more space between crystals, so it's a lot more forgiving. But, it also moves more when you're cutting, which means it's more likely to roll or flatten out, which means your edge doesn't stay sharp as long.

But here's where it gets interesting. Because they're different structures, the different shapes don't fit together perfectly. That's why it's best to clay in a wave pattern, rather than a straight line. Nature loves curves, and abhors a straight line, after all, and it's more aesthetically pleasing. But it ALSO provides a structurally solid shape and more surface area to minimize any stresses between the transition.

Anyways, that's one reason I prefer a through-hardened complex steel like 3V to a simpler carbon steel. You get consistent carbide formation throughout the blade, and 3V retains appropriate toughness for a sword even at 60 RC. The structure of the carbides I think provides more surface area contact between crystals and a more geometrically stable shape along the appropriate axes, which is why it's so tough at high hardnesses, which also enhances wear resistance.

Mete would be a good one to talk to as well about metallurgy. I've mainly been experimenting with the theory behind the way that the crystalline structures interface, having learned enough to satisfy myself that 3V (or hopefully 4V now that's out) can, with the right heat treat, be amazingly good stuff.

There's a lot more that goes into it. Modern steels have more consistent and smaller grain size, which means more consistency and hence structural stability.

The short version really should be this: Pick a sword not because it has some special steel, but because you know that it has a really good heat treat for that steel type, and that the heat treat maximizes the qualities that you want it to have. If you're mostly interested in its ability to cut pool noodles and bash on steel pipes, you may want a very different kind of blade from the one that STeven might prefer for its cutting ability. Toughness in simple carbon steels may come at the expense of sheer cutting ability, because that's almost always a tradeoff. I've got one made by a local smith that's VERY tough, and his work has been used to bash on engine blocks. But, edge retention and the quality of the edge that it can take is considerably inferior to, say, my Tiger Elite (or any of my own blades), which I would NEVER take to a steel pipe. You need a steel and heat treat that fits your needs. That's why reading stuff online, most of which is written by people without any real knowledge, can only take you so far. You need to decide what you want out of your sword, and take those reviews with a grain of salt. Most are written by people who know very little about swords, metallurgy, swordsmanship, cutting, etc, and thus need to be read with a discerning eye to catch the nuggets relevant to your interests.
 
crimsonfalcon07 said:
The short version really should be this: Pick a sword not because it has some special steel, but because you know that it has a really good heat treat for that steel type, and that the heat treat maximizes the qualities that you want it to have. If you're mostly interested in its ability to cut pool noodles and bash on steel pipes, you may want a very different kind of blade from the one that STeven might prefer for its cutting ability. Toughness in simple carbon steels may come at the expense of sheer cutting ability, because that's almost always a tradeoff. I've got one made by a local smith that's VERY tough, and his work has been used to bash on engine blocks. But, edge retention and the quality of the edge that it can take is considerably inferior to, say, my Tiger Elite (or any of my own blades), which I would NEVER take to a steel pipe. You need a steel and heat treat that fits your needs. That's why reading stuff online, most of which is written by people without any real knowledge, can only take you so far. You need to decide what you want out of your sword, and take those reviews with a grain of salt. Most are written by people who know very little about swords, metallurgy, swordsmanship, cutting, etc, and thus need to be read with a discerning eye to catch the nuggets relevant to your interests.
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Hey CF, hope all is well with you and yours.

The swords that I am interested in handle well and cut traditional Japanese cutting media.

I have studied JSA at a "real" dojo for over 15 years, and am only starting to get a feel for it all, but I can explain the "what and why".

In traditional JSA, we are interested in cutting flesh or "flesh like" targets with simulation of armor and without. The cutting media starts out with tatami omote, which is the straw mats that people in Japan have traditionally used as carpet in their homes. A single mat, soaked in water and rolled up very well simulates an arm, especially with a 1" bamboo core rolled inside. This is due to the fact that bodies became prohibitively difficult to procure as Japan moved into the "modern" age. Prisoners were no longer considered viable cutting targets...it was considered barbaric.

I leave it to you all to consider if it is more humane to kill a prisoner judged to a life sentence with a quick and expert sword stroke or to rot on death row for the rest of their miserable lives.

Anyway....for those of us in JSA discipline, the human body is the "ideal" test of a sword, and not pool noodles and not steel pipe. We know what the sword is supposed to cut and we try our best to replicate that as a test medium.

In general, we are not pretending to be at war with zombies and we realize that walking around the streets of >>>>fill in your city name is likely to wind us up in jail or a mental facility....but we train with the best techniques that we can with the best steel that we can because we believe that it results in being a "better" person, and sometimes the old ways are the best ways.

There is a reason why the sword is one of the Three Treasures of Japan, and it is a good reason.

I'm confident that of the many swords I have owned and cut with, the two L6 swords I have and the CAS Hanwei Tiger Elite and Shinto Elite will cut the way that I want them to and how I want them to, and the rest is entirely up to my skills or lack thereof.

Best Regards,

STeven Garsson
 
Good information STeven, and exactly why I figure that what you look for in a sword will differ from what the average sword buyer might look for. Most of the latter seem more interested in the ability of a sword to cut down trees and other similar tasks, which require a very different type of blade than one that a serious practitioner of a sword-wielding martial art might look for.
 
Good information and personal insight from both of you. I think Willie pretty much nailed it with the steel vs. steel not being as important as properly heat treated steel. As far as steel is concerned, it seems to be an extremely opinionated area of discussion. So it's good to have some different points of view. To Steven I would say that some backyard cutters do not necessarily have access to tatami mats, hence the pool noodle and rolled newspaper cutting. In some cases, this can be a cheaper alternative. As to the "bashing steel pipe" comment, the only time I have seen or heard of this is in demolition videos. Personally, I feel what one wants to cut with his sword is his own business. Although, if you plan on keeping your sword in one piece, it's probably not a good idea to hit something harder that said sword. To CrimsonFalcon I would say that the steel question gets asked a lot. Everyone has their own opinions, from the novice, to the practitioner, to the metallurgist. I feel that is in an important question to ask. Willie answered this question pretty fluently for me. As for yourself, you share the same general consensus, steel vs. steel doesn't matter if it is proper heat treat. You then followed that up with 3v being the best steel. Like I stated previously, everyone has their opinion. That's why we ask. I appreciate all the factual knowledge you stated about said steel. People would like to know! Very interesting stuff. I personally appreciate you guys finally weighing in on this. As far as the OP is concerned, would you mind chiming in on that subject? If nothing else then for the benefit of everyone that wants to know you guys' opinion. After all, that's why we are here. Thank you guys!
 
This has been an interesting discussion. The one question for me to research is the idea that "every sword has a hamon...." I suspect this is true with simple steels due to the geometry and harden ability. With high alloy steels it probably isn't.

In light of Steven's comments on what swords are meant to cut, almost any carbon steel over .4 or .5% carbon will do the job perfectly fine!

Just for info, 15n20 is the Swedish version of L6. The nickel in those steels provides a lot of toughness without forming large carbides. It was designed for sawmill use primarily. It's not "the best" but I use a lot of it and know my heat treat of this steel pretty well.
 
Steven, since I am just starting on the sword journey, do you have any recommended resources on Japanese sword construction and geometry? I did a tango from internet pictures, and it's not anything genuine at all. I would like to make a "real" sword or as close to possible as my skill allows.
 
Willie71 said:
In light of Steven's comments on what swords are meant to cut, almost any carbon steel over .4 or .5% carbon will do the job perfectly fine!
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If the heat treat is dead on....maybe.

The cutting media we use is generally static, in that it doesn't move, lol......but we do.

The bigger the target(they can get quite big quite fast, an 8 mat roll will have over 12" of diameter) the greater the propensity for the sword to twist in the hand, and this results in a bend in the sword that usually takes a set, and it is a twist set which renders the sword pretty much useless....as removing twists from the blade is almost impossible.

So....for us....we need a "tough" blade as well as a sharp blade. If the edge gets too hard, it gets "chippy", too soft and it bends/twists easily.

Dan Keffeler is building a sword that I will probably have the opportunity to cut with that will be mounted traditionally, with untraditional materials....this is quite exciting. It will only be used to cut tatami omote and bamboo, as the request has been to cut traditional media.
Willie71 said:
Steven, since I am just starting on the sword journey, do you have any recommended resources on Japanese sword construction and geometry? I did a tango from internet pictures, and it's not anything genuine at all. I would like to make a "real" sword or as close to possible as my skill allows.
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Stuart Branson is working well in the discipline, you might contact him. I recommend the two Yoshindo Yoshihara books written with Leon Kapp, and I also recommend getting your hands on a CAS Hanwei Tiger Elite sword....prices just came down, you can re-purpose the fittings and all the blades I have seen very closely approximate the "ideal" for weight and construction of a "battle ready"(I hate this term) sword. Rich Stein has a website that is pretty comprehensive as well. Pretty sure you can just google "Rich Stein Sword" and wind up there.

If you are looking to use a tanto as a study piece, both the CAS Tori tanto and the CAS Great Wave tanto are tremendously well done. I see the Tori available for less than $400 online. It has a very nicely done blade and should serve you well for a baseline.

Best Regards,

STeven Garsson
 
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Thanks Steven. Kult of Athena had a last generation factory blem for $760.00, so I ordered it. I will look into those books, and will touch base with Stuart once I get started, when I have specific questions.
 
Willie71 said:
Thanks Steven. Kult of Athena had a last generation factory blem for $760.00, so I ordered it. I will look into those books, and will touch base with Stuart once I get started, when I have specific questions.
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Which model of sword, by what manufacturer?

Best Regards,

STeven Garsson
 
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crimsonfalcon07 said:
Good information STeven, and exactly why I figure that what you look for in a sword will differ from what the average sword buyer might look for. Most of the latter seem more interested in the ability of a sword to cut down trees and other similar tasks, which require a very different type of blade than one that a serious practitioner of a sword-wielding martial art might look for.
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Construction and materials aside, where do skills fit into all of this? I would suspect that a skilled practitioner could pick up a cheap barely sharpened sword and make a clean single cut right through a 2x4; while a novice equipped with the best sword that money can buy will just as likely break the sword while barely notching the wood. There is a lot more to sword use than metallurgy, it is probably the least important factor.

n2s
 
Iv been practicing kenjutsu for 4 years and martial arts for 21 years.

While the quality of metal does play a big part in combat, the shape and balance of the sword are key.
I have a Ronin Hagakure and it's my most used katana in the dojo.
I also got a cold steel warrior because I heard great things about its cutting ability. While it does cut well, the Ronin is world's more agile because of its superior balance. Just a much better designed blade following traditional shape. It makes the cold steel feel like a bat

Guys that bring in katanas that are traditionally made, with a nice pretty hamon and bo-hi, soon switch to a monotempered dojo katana to handle the abuse. No wall hangers in class. And the extreme torture tests the monotempered steel survives, and still retains a good edge, I wouldn't consider a differentially hardened blade for combat either.
 
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