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A2 or S7 for a Katana?

Dec 20, 2005

I was wondering if anyone's made a Katana? I know, it's kind of a weird project, but I like the challenge and thought it would be kinda cool.

Out of A2 or S7, which one would you use? Which one files/ grinds easier? The reason I narrowed the steel choice down was that I'd like to use an Air hardening steel that would work well in use and is affordable. (I would have considered one of the 10xx series, but I don't have the facilities or space to heat treat something this large).

Any recommendations would be really appreciated.

P.S. Anyone know the stock thickness I should start out with? I'm thinking 3/8"? :confused:

Thanks! :thumbup:
Not sure how you are going to HT an air hardening steel if you can't HT a 10XX steel.
I would suggest you rent or purchase Wally Hayes' video,"Katana". In it he shows how to make a katana by stock removal,using 1080 steel. He shows how to do the HT with a backyard setup (no ovens or forges).He makes a tsuka (handle) and saya (sheath). None of the materials,including the steel, are expensive. The project is doable by someone with basic skills, but is usually tackled by medium to advanced makers.
I will caution you that a katana is a big project without a belt grinder.A disc grinder would be a minimum if you intend to mainly use files and sandpaper. The finishing and polishing is by hand ,anyway.The other caution is that in polishing,you are sharpening.It gets to be a situation of polishing a three foot straight razor.Have all the first aid supplies ready,and pay careful attention to what you are doing while polishing.No distractions!You will get a cut anyway,most likely,so be prepared.
Again,get Wally's videos (it is a two volume set).It is available to rent from smartflix.com . http://smartflix.com/index.php?main_page=product_info&products_id=2253

Alan has corrected me - 1050 steel is what Wally used.
Wally Hayes' video,"Katana". In it he shows how to make a katana by stock removal,using 1080 steel.
I thought it was 1050 steel?
and I think he used 1050 steel with a water quench because without going for a nice hamon line on the Katana, there is little reason to go to the trouble to make one.
The hamon is part of the reason for making a Kat.
I guess you could make a air-hard steel and just cut it to the curved shape you want, but with just a little extra work with a different steel you would have a blade thats so much more fun to view.

If I could suggest something, it would be to do a little thinking about what you would need to work with a water-quenched steel and going for a nice hamon.
Alan, I think you are right.Wally used 1050. When he would say it with his accent it sounds like 1052steel,but he says 1050 tool steel.
The last one I made was 1080.
When he would say it with his accent it sounds like 1052steel,but he says 1050 tool steel.

As a matter of fact, I had to play that darn video over and over to try to catch the number he was saying.
At first I was 100% sure he said 1052 steel, so thats what I went looking for on the web. That turned out to be a pointless quest as 1052 steel was a hard steel to find.

Then I listened again the the video a few more times and came to be more-or-less sure that he says 1050 steel.
I got some of the 1050 steel and made the katana just as is seen in video.
Then because it was so thick I tried 8 more times with a thinner steel that was less than half the money...I cracked every one.

The water quench is a nasty bit of fun.
However when I finialy got it to work I ended up with a great hamon and swords with a real hamons that are worth looking at .

So again, I would make the suggestion that in place of any type of air-hard steel, that you would think of getting a different steel that would allow you to do a real water-quench and end up with a hamon.

The tool you will need to get before you do a katana is a belt grinder.
I know you could just use files, but, oh BOY that would be a lot of work.
But if files are all you got, then you still can do it!
To do a water quench all you will need is a home-made forge ( just a pipe with holes in it and a blower like a shop vac or something) and a water quenching tank, (just a tarp)
I was going to have Paul Bos heat treat it for me. He only does air hardening steels and the max length is 32".

I have a grinder. Just planning to clean up with a file and sandpaper.
well. if thats the plan

....But I still have to suggest that with all the work you will have to do anyway, that in the end I still think that a katana made from a water-quenched steel is going to be more fun to look at than any air-hardening steel.

Now I dont have a clue about the system that your heat-treater guy might use on your sword, but I dont "think" it will give you the result of a hamon.

And....You "need" a hamon.
A knife does not need a hamon.
A sword does not need a hamon.
But I think a Katana without a hamon is just a long pointy thingy.
however it might be a good "first step" on the road of learning how to work with steel and how to design things. But I still have to suggest you think about a water-quench as seen in the Wally Hayes KATANA video.
A hamon and the resulting difference in RC hardness is a halmark of a Shin-Ken. I do not know of a way to execute a hamon with airhardened steels. I have used working Shin-Ken on tamashigiri mats and fresh and dried bamboo. I can tell you that the shock resistance of the spine allows you to cut things such a long and thin sword should have trouble with. Cheaper Iato Shin-Ken were always vastly inferior in actual cutting and bent easier when cutting mats and bamboo together. If you want the real thing you will need a hamon for proper function. If there is a way to do this with air hardened I would love to know as well.
Phill Hartsfield uses A2 and his website states - "Phill's blades are tool steel, RC 60, and as the hamon indicates, they are edge hardened. This is done in the heat treating, which he does himself"
This picture is from quintcut.com/

The lighting doesn't do this knife justice but you can see the hamon.
You can ask him..... but I doubt he will give away his secrets.;)

I used to have a small knife of his done in A2 and it held an edge better than anything else that I've owned. (lost it at work)
His knives/swords are scary sharp. :eek:
So you would do it like this?
have fire bricks in the oil producing the right height of oil left above the bricks. Then quench the edge by setting it on the bricks leaving the spine of the blade out of the oil for the initial part of the qeunch? I have seen people do this with knives but how would you get a curved hamon across the length of the blade using this method? Or am I misunderstanding the process for oil quenching to produce a hamon? Also I have always understood the complex and sometimes smith specific hamon types to come from the way the clay is applied. Do you just have to settle for whatever wavey pattern emerges from the oil quench hamon? I know you can rock it side to side a bit to produce a more wavey hamon but it seems like this would produce a random pattern as opposed to a consistent pattern.
I read your post,,,,

You have to back-up a bit...

But I cant tell you what to do, I can tell you what I have done that seemed to work for me...
I only know how to get a hamon on 1050 steel by the use of a WATER quench of a CLAY covered blade.

#1 - You work the blade into the shape you want, leave it a bit thick along the cutting edge so that the extra steel thickness might help keep it from cracking,

#2 - You coat the sides of the blade with fireplace clay. You dont have to coat the cutting edge, Wally Hayes does not, However if you are useing a different type of clay as real japanese bladesmiths use, then you could do as they do and also apply a very thin clay coating to the cutting area.
However I just leave the cutting areas dry and clay-coat the sides near the spine.

#3...Heat in a fire until the whole cutting edge will not attract a magnet

#4, do what is called an "Interupted quench" in water thats already warmed to about 106 temp.
Dunk in the water for a few seconds, lift out for a few seconds, dunk again, lift again, dunk, lift, dunk.,lift..etc.

#5 temper in kitchen oven for an hour at...300?

#6 work the sword cutting edge down to sharp, sand or file to shape you want.

#7 etch....and view hamon
Alan, thanks for the input. I am wondering about the method for a2 though. I am not shure if people are saying coat the a2 in clay and oil quench or if they are saying to do it like in my above post. By just placing the cutting edge in the oil first to produce a hamon. I have seen people get a hamon on a fnife in this method, but am not shure how you would get the long curved blade to do this. So... do you just clay coat the balde minus the cutting edge and oil quench like normal A2?
I can not help you with A2..I know NOTHING about it.

I have heard of very few who can get a real nice hamon with an oil quench,,,some guys can....but I have heard of more that could not..

I do not think as i read over your question that you would see much of any advantage in holding the spine out of the oil,,,,,
I just have never-EVER heard of a Katana that was oil quenched in such a manner.

I know nothing about what A2 would do in such a situation...

I just dont "think" you would end up with the type of hamon you are aiming to get buy the use of such a system.....
No, I dont think the oil quench method I described would work for anything other than knife blade of much smaller size. They must be talking about apyling clay then quenching. From what I was told about doing it on a knife blade is that the quench cools the spine slower than the cutting edge thus giving you a different RC on the part quenched first and second (the whole blade is submerged after short time of just the cutting edge bieng in the oil.) This was explained to me to be a cheap easy method of diferential tempering. I guess I had never heard of air hardened steels bieng oil quenched, so for some reason I was thinking it was some nonclay using method such as the one I described. But now that I have had a little time to think about it, it makes sense that if you can oil quench it just use the clay I suoppose. A2 Katana blades are a bit off in the distance for me anyways, but I hope to get to them as soon as I feel up to it. I will most likely start with metals and process such as you described. Thanks for the input, I think I just confused myself overthinking the situation (underthinking maybe =P ).
A2 Katana blades are a bit off in the distance for me anyways, but I hope to get to them as soon as I feel up to it.
Hey I gota ask:...Why do you dwell only on A2 steel for a Katana?
It's a tricky steel to go for a hamon with.
Are you sitting on a liftime free supply of A2 or something?...LOL

If I were to give you one last word of advice:,,,There is a Wally Hayes video called "KATANA" that shows you how to go step-by-step and make a Japanese-style sword.

Mr Hayes does each step in such a way as to make it easy for a new guy to copy...No hammer forge work, just a bunch of grinding and fileing and sanding...No tricks, no need to be handy with tools.

Wally Hayes show you how to make a type of forge to heat-treat the steel . You make it out of everyday items found in the backyard of in a scrap pile, and how to build a 4-foot long quench tank out of a common tarp.

Perhaps someone has up-loaded some of this video onto YOUTUBE?...try a Google search for him.

Anyway, try to get a copy of that video set, and it will show you the path.
Thanks, I actually wasnt thinking of A2 at all, it just came up in this thread that you could get a hamon with it. I will make my first swords out of good ol carbon steel. I will watch Mr. Hayes's viseo for shure. I have seen it many times, just havent picked it up yet. I really want to forge the blade but wont have the equipment or setup for a bit. Maybe I'll knock one out stock removal. A2 just came up in the original post and I was interested to find you could oil quench it, I dont know alot about A2 either. However R.J. Martin's Tantos are made of the stuff and its wicked sharp, would be interesting to see it in use in a Shin-Ken. My biggest concerns are sharpening the blade as I would like to use traditional stones to acomplish this, but I'm getting ahead of myself. =P
I don't know why anyone would want to differentially heat treat A2. It highest impact resistance is at HRC 60. If you lowered the hardness of the spine, you would weaken the blade. A2 does have a large window of time to get below the Ms temp without getting into Bainite or Pearlite phases, so maybe you could get some knind of Hamon without weakening the blade. I have not tried it that way.

I forge A2 knives from round bar on occasion, so you wouldn't have to do stock removal. It is not easy to forge, however. If you have a power hammer, it would be easier-I do it by hand.
I think Criswell makes some A2 Katanas and I don't think I've heard much negative about his stuff except that it's not terribly traditional.