i'm obviously a big fan of japanese swords, but if you ask any metallurgist, he's going to tell you that modern monosteel is a better way to go.  pattern welding by definition creates inclusions that compromise the structural integrity of the steel.  this was acceptable 400 years ago because it was the best way the japanese had to homogenize their billets, so the tradeoff was worth it. modern crucible steel doesn't require tradeoffs.

Yup. This thread is going to cost me money. Curse you, goose molester!

As far as yaris and naginatas...

We have a guy that bought his in Japan.  He took the blade off and had to get that shipped through customs, but the pole he brought home on the plane.  For the long oversized stuff he wraps it up (protective covering) and tells the counter something to the effect of "over-misu" for oversize. ( not sure on spelling, but whatever is the Japanese equivalent). They go "oh, over-misu", and stick it on the plane. He gets home and a few weeks later the blade arrives and he pins it back together. Has a few polearms he brought back recently.

Ymmv

As an aside, I knew a pole vaulter that would do the same with his bag of poles on flights to away-meets.

I would really like to find an unpapered authentic, complete, $1000 waki.

Mostly to have a study piece for my own craft.

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Email sent DK-Prof

Oh nice, thank you.  That's exactly the kind of piece I'm looking for.

Do you have any that have been used in duels or anything?

I'd agree with you EXCEPT that you would need to make an apples to apples comparison.

A Japanese blade made with a hard steel core and a mild steel jacket would need to be compared on an even footing with equivalent modern steel formulations in an equivalent configuration.

Comparing that multi-element Japanese blade to a piece of CRS would have only one outcome:  Japanese blade wins.

Now compare to a sword made with a CRS jacket and a Martensitic steel core of the type used to make razor blades.  You'll get a different result.

I have always wanted a decent, real Japanese blade. I've even looked at buying tsuba, which are an art form in their own right. I just don't want to get ripped off on eBay because I don't know enough about them. I'd buy a fake first thing with my luck.

I just saw this episode the other night:

Expedition Unknown
Season 1, Episode 11
Samurai Sword of Power
Josh searches through various ancient shrines in Japan
looking for the mystical Honjo Masamune sword.
During his travels, Josh learns the ways of the samurai and is educated on how to forge his own sword.

I had no idea that families all across Japan were ordered to turn over their family heirlooms as per the surrender order. Lots were "lost" and never handed over.  A lot that was were given to USGI's to take home as spoils of war.  The missing Honjo was documented turned in, but according to military records, the name of the soldier it was given to never existed in the US Army.

His name “GI Joe, description, white with round eyes”

i'm confused--you compared japanese pattern-welded steel against 1095 bar stock.

i'll take the steel used for flat and coil springs over a laminate that is empirically shown to bend under normal stress loads.

Well shit. I missed out on that one by $7.

I do wonder after researching that bladesmith, if that signature was authentic though. No matter for my purposes.

No I took it as being Shinkai's father. But that conflicts with the "1650s" date since he apparently died in 1652.

FWIW this is my current project and why I'm determined to buy a true nihonto example, doing this from pictures only is a pita.

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Still not crazy about the ito.  May use leather.

@kpel308

Yes, it is mostly from Magnum, but it was a gift when I was working a gig about twenty years ago, and worn it daily since. So it holds multiple meanings for me.

An avenue you may want to look into for sword work is the Bujinkan. Most blade work is streamlined and simple, but it’s pieces of traditional systems going way back. That’s where my exposure to YSR came from.

Interesting.

Yup that's why it was a perfect example for me. Everything I need to see and a roll of the dice at possibly being an incredible deal

I think that the response I need to make with response to hard/soft steel and core and jacket is that there are several construction types for japanese swords, using anywhere from two to seven pieces of steel to make the blank.

In any event, it's the edge steel that's the harder grade.    Some use three or more grades and the construction varies. What I said earlier concerning distribution of harder and softer steels is correct for some construction types, and dead wrong for others.   So let's actually have a look at the construction types to see what's what.



And when I refer to spring steel, I will confess in absolute honesty that I had not previously researched what steel grades are used for spring steel and it turns out that even clock mainspring steels are often made of 1070 to 1090 grades and 1095 is commonly used as spring steel as well.

I've worked with some 1095 before. I've made parts out of it on both a lathe and a mill but I've never heat treated it. In its soft state I've never found it to be very impressive.

So I've learned some things tonight.  Good.  That makes the day worth it.

Solid parts made from laminate of different materials absolutely impacts the properties of the finished component.

There are also absolutely inherent stresses on those laminates, depending on the individual material properties, that don't occur in monomaterial parts, particularly with steel that will be hardened.

For example, this san mai blade is wrought iron cladding and a W2 core. Wrought iron doesn't go through the austenite martensite phase change that W2 does when quickly quenched from 1465 degrees, so it stays soft, and as the W2 core grows and shrinks through the phase changes, it conforms to the W2.
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However,  in this example of AEB-L stainless clad san mai over 1084 steel,  there is some phase change quenched from 1500f.  Because the growth and shrinkage rates are so different,  the AEB-L cladding essentially ripped the 1084 core apart.   The 1084 was growing while the AEB-L was shrinking.
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These two examples illustrate the importance of property pairing in laminate steel.  The first blade was a good pairing.  The second can be made to work, by cold peening the AEB-L after welding and before quenching, to essentially pre-stress it lengthwise and give the 1084 the room it needs to move,  but absent that kind of treatment it's a poor combination.  A good way to depict internal stress possible in laminates though.

Because the alloys being used in the nihonto blades being discussed are primarily only small differences in carbon content, the stress of being quenched together at the same rate is much closer to the first example than the second.

My destructive testing with blades like the first tells me they will bend further (and concurrently surpass yield strength and enter plastic deformation)  sooner than a monomaterial blade of the same physical dimensions,  which will often break as soon as plastic deformation occurs depending on hardness and thickness.  So they are tougher, but not as strong (strength being a component of hardness).

That's why you see a traditionally made katana wrap itself around an ice block on Knife or Death, while a through hardened monomaterial blade either isn't phased by the test,  or fails spectacularly with a clean break.

Personally,  I see laminate and differentially hardened blades experience plastic deformation under less stress than required to cause a catastrophic failure of a monomaterial blade, while on the other hand, when that point is reached by the monomaterial blade, it generally becomes scrap while the laminate blade can be repaired by straightening it out.

I watched  program on NHK how they make these modern swords, and it is quite complicated and takes quite a bit of work. First they gather the iron ore and process it into steel. Where they get the ore and how they process it into the steel is a closely guarded secret. They have 3 guys working on it, 2 guys with sledge hammers and a guy holding the red hot slug; the pound it over and over again and again.

Anyone want to buy a Japanese NCO sword?

Shoot me a PM with info.

I applaud your desire to learn polishing.

Begin by getting this book:

https://www.amazon.com/Craft-Japanese-Sword-Leon-Kapp/dp/1568364318

It has a pretty good primer on the basics of polishing.

As for the stones,  synthetic Japanese waterstones are used for all but the last stages of polishing and they are not expensive.

If you just get the grades mentioned in the book, you'll be all right. You don't NEED to buy extra in-between grades.

I know that the Suehiro brand of stones is well regarded by polishers.  Many grits are available but again, you only need a few grades.

You don't want the ceramics. You want the more traditional waterstones.

But when you reach a certain stage, Japanese natural stones are the only option that will yield the desired finish and appearance.

There simply is no substitute for the Uchigomori stones.

While very fine Uchigomori stones can be very expensive,  perfectly decent "sword grade" bench stones can be had for about 250 dollars or so.

That's sort of pricey but really not that bad at all.  I'd have to say that if your investment in stones is not more than the cost of the blade you're working on,  that's not a bad deal.

You'll also need a hard steel or carbide burnishing needle.  You can make one from a worn out rat tail Nicholson file.  Belt sand all the teeth off and sand through several grades of grits up to 2000 and then buff it to a perfect mirror shine on a buffing wheel charged with green chrome polish.    Or you can use a high polish solid carbide end mill's tool shank.  For a convenient holder, get a go/no-go gauge handle with a collet sized to fit the tool shank. (1/4" is good.)

That's for burnishing the flats and the spine.

I'm familiar with the traditional posture and polishing position used by polishers.  It does look like it'd be hard on pretty much everything.

If I were to do this, I'd try setting up my workspace in a kneeling position on good cushions with the work table being slightly elevated, with a simple mechanism attached to the surface
that clamps the polishing stone in place from the side so you can dispense with that wooden stick that clamps the stone down that is manipulated with your foot.  (Fumaegi.)

Working on your knees on a decent cushion would have to be more comfortable.

Very interesting thread.  Thank you for posting.

Awesome thanks for sharing!

Yes.

Regardless of the construction the time and temperature of forging it is going to cause enough grain growth that normalizing and then refining the grain (nucleating new grains) by thermal cycling at approximate austenitizing temperatures, then going to fine spherodite with a subcritical anneal is going to be ideal for optimal performance. So the main question is the core, or jacket, or whatever dissimilar material to the cutting edge: How does it react to the austenitizing cycle being done to the cutting edge? The only way to avoid it being differential hardening, and even that not avoiding it completely.

Larrin Thomas (http://www.knifesteelnerds.com) is doing toughness testing.  I plan to send him some laminate billets for Charpy testing since he hasn't done any yet and is curious about it as well.

What time period is the helmet from?

I don't see any blades in that picture which have a hard steel core and a soft steel jacket.  What a strange way to say "I misspoke."

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