SRS 15 - D2 on steroids!

nozh2002 · Apr 8, 2006

Japanese powder metallurgy stainless high speed steel -

SRS 15 -

C=1.5
Cr=13
W=1.25
Mo=2.75
V=1.5

D2 -

C=1.55
Cr=11.50
V=0.90
Mn=0.35
Mo=0.80
Si=0.45

So it is D2 with pump up contents of Vanadium, Molibden, Chrom and Tungsen added and 63HRC. They use it as a core for laminated blades. So far only Fallkniven use it for kitchen knives. I Japan G-Sakai doing several nice utility knives with it like Bosen Enkuto, but not too much.

I hope our knife manufacturers notice it and will start using. Japan knifemakers came up with really good staff, however it looks like interest to knives in Japan is not to too big, so they do not enough support to continue making this things.

Thanks, Vassili.

Gringogunsmith · Apr 8, 2006

nozh2002 said:
Japanese powder metallurgy stainless high speed steel -

SRS 15 -

C=1.5
Cr=13
W=1.25
Mo=2.75
V=1.5

D2 -

C=1.55
Cr=11.50
V=0.90
Mn=0.35
Mo=0.80
Si=0.45

So it is D2 with pump up contents of Vanadium, Molibden, Chrom and Tungsen added and 63HRC. They use it as a core for laminated blades. So far only Fallkniven use it for kitchen knives. I Japan G-Sakai doing several nice utility knives with it like Bosen Enkuto, but not too much.

I hope our knife manufacturers notice it and will start using. Japan knifemakers came up with really good staff, however it looks like interest to knives in Japan is not to too big, so they do not enough support to continue making this things.

Thanks, Vassili.

KOOL !
UM.
Japan was/is the master of steel before hillbilly boys roamed the earth.
You probably wont find too many " tactical folders" and the like but sharp, high quality, steel abounds.. ceramic too !
I'm eating sushi tonight..

The Japanese folk use sharp steel for tools.. NOT show...

The good old boys I buy my fish from, in Niigata, would laugh at some dipstick cutting bamboo or chopping 2 by fours or bone ,with a sheath knife.

" Dougrass ? He no have chainszraw or hand szraw ?"

" Dougrass. Why he cut steel with belt knife ? We use nibblers and shears"

He ruin his knife.

Ahhh the refreshing reality of those with brains..

Gringogunsmith · Apr 8, 2006

I just got me a tanto sword in a wood box from ??? years ago.
It came as a gift with a fish shipment.
A little pitting and I guess bugs ate the handles off over the decades.

Anyone up for a decapitation test when she's done ?
I wont put it in a vice and see houw far it will bend

nozh2002 · May 2, 2006

I did some chopping with it and quite impressed! Time to time I clean path near the house from bush. I am using for this one or other knife from my collection. This is freely hanging branches and I chop them out trying to keep straight line. Knife should be sharp and fast for this kind of job - like tactical I assume.

Bosen Enkuto so far the best from what I tried! One slight touch and branch is cut almost without any visible effort from my hand. And no indication of any sharpness degradation! Shaving sharp as it was out of the box. And I also did some cardboard cutting few weeks ago!

I highly recommend this steel!

Thanks, Vassili.

Cliff Stamp · May 2, 2006

Gringogunsmith said:
The good old boys I buy my fish from, in Niigata, would laugh at some dipstick cutting bamboo or chopping 2 by fours or bone ,with a sheath knife.

There are many Japanese knives made to do all of those things.

nozh2002 said:
I hope our knife manufacturers notice it and will start using.

BG-42 is a high speed stainless with a similar composition, it never gained much popularity with knifemakers, comments from users were generally solid. Heat treating high speed steels is very demanding.

-Cliff

nozh2002 · May 2, 2006

BG-42 does not look so cool:

C=1.15 vs 1.5!
Cr=14.5
Mn=0.5
Mo=4
Si=0.3
V=1.2

Much smaller Carbon contents, no Tungsten, less Vanadium and HRC less then 63 as I understand.

Japanese manage to produce a lot of kitchen knives like this - so they able to do proper HT in mass production.

Unfortunately there are only 3 utillity knives by G-Sakai with this steel. I wish they will make some folders too.

Thanks, Vassili.

Cliff Stamp · May 2, 2006

nozh2002 said:
BG-42 does not look so cool ...

Same family, high speed stainless, if you want more wear resistance just go to the high vanadium series, S60V, S90V, or S125V if you want to get extreme. There are also high D series steels beyond D2 which have much more carbon and alloy carbides, D7 for example.

...and HRC less then 63 as I understand.

These class of steels can all reach ~65 HRC, ATS-34 can as well for example, hardness isn't a problem, you just have to soak them hot, use an aggressive quench and cold treatments, it is somewhat demanding but far less than hardening HSS.

-Cliff

Larrin · May 2, 2006

Cliff Stamp said:
Same family, high speed stainless, if you want more wear resistance just go to the high vanadium series, S60V, S90V, or S125V if you want to get extreme. There are also high D series steels beyond D2 which have much more carbon and alloy carbides, D7 for example.

These class of steels can all reach ~65 HRC, ATS-34 can as well for example, hardness isn't a problem, you just have to soak them hot, use an aggressive quench and cold treatments, it is somewhat demanding but far less than hardening HSS.

-Cliff

SRS-15 isn't a stainless, so it couldn't be in the same family. I couldn't imagine it squeaking by with enough corrosion resistance with chromium that low and the carbon that high.

orthogonal1 · May 2, 2006

Did a google on that Bosen Enkuto knife. Looks very utilitarian.

The blade looks pretty thick, though.

I'd be happy if more +62 HRC knives were sold stateside, period.

Cliff Stamp · May 2, 2006

Larrin said:
I couldn't imagine it squeaking by with enough corrosion resistance with chromium that low and the carbon that high.

S30V has 1.45 C and 14% Cr, S90V has 2.3% C and 14 %Cr. You have to consider the effect of the other alloy carbide formers which are stronger carbide formers than chromium. As well with an increase in carbide fraction the amount of free chromium needed for corrosion resistance decreases. If for example 50% of the steel is carbide you only need half the necessary chromium for the steel to be stainless.

-Cliff

nozh2002 · May 3, 2006

Larrin said:
SRS-15 isn't a stainless, so it couldn't be in the same family. I couldn't imagine it squeaking by with enough corrosion resistance with chromium that low and the carbon that high.

Formally 13% is stainless like 420. It may be not corrosion resistand but by definition more then 13% means stainless.

This is bit more about Bosen Enkuto:

http://www.bladeforums.com/forums/showthread.php?t=397335

I am quite impressed with cutting ability and ergonomic.

Thanks, Vassili.

nozh2002 · May 3, 2006

I have fax from manufacturer about this steel it is on Japanese - I can understand only composition and also it has 65 HRC somewhere inside Japanese characters. However I dont really know is it blade hardness on Bosen Enkuto.

Thanks, Vassili.

Cliff Stamp · May 3, 2006

That is a really nice looking knife, I don't know if I would want that style of steel in that type of grind though. How are you sharpening it?

-Cliff

Larrin · May 3, 2006

nozh2002 said:
Formally 13% is stainless like 420. It may be not corrosion resistand but by definition more then 13% means stainless.

That isn't actually true, it doesn't necessarily matter how much chromium is in it, only how much is in solution after heat treating; however, I am no longer trying to argue that SRS-15 isn't a stainless.

nozh2002 · May 3, 2006

Cliff Stamp said:
That is a really nice looking knife, I don't know if I would want that style of steel in that type of grind though. How are you sharpening it?

-Cliff

I do not need to sharpen it so far - out of the box sharpnes was excellent and it hold it quite well. Blade is laminated and SRS15 core not too thick - so I do not expect too much troubles.

Thanks, Vassili.

Cliff Stamp · May 3, 2006

How stainless a steel is depends on the free chromium (and lots of other elements such as nitrogen), however what it takes to classify a steel stainless is generally the chromium content.

-Cliff

HoB · May 3, 2006

Mmmh, while I am sure you can get some hints from the composition, I don't understand how you can possibly say: "Hey, this must be a good blade steel"...or even worse "hey, this must be a better/similar bladesteel than D2/BG42" by simply looking at the composition? This can only lead to hype and hysteria. You have no clue what is going on in that steel on a structural basis. For all you know, that amount of Mo and the added W might change the properties such that it resembles in no way D2.

With all due respect but the statement alone that BG-42 "does not look so cool" underlines just how questionable the entire thread is. There are many very knowledgable people (like Sal just to name one) who hold BG-42 in very high regard (asside from the fact that it is supposed be difficult to heat treat). To dismiss BG-42 or any bladesteel based on its composition is just plain madness. For crying out loud, would you have figured INFI to perform as it does, based on its composition? The affects of Kr for example are mostly uninvestigated.

I mean, sure you can tell a tool steel from a HC steel from a basic stainless steel....but we are talking about highly alloyed and complex steels here. Metalurgy is more an art than a science (guidelines vs. strict predictability)! As the this thread clearly points out, you can not even tell how corrosion resistant that steel will be (though it meets the definition of a "stainless steel"), based on its chemical composition. How can you possible try deduce any more complex properies by simply looking at the composition?

All this leads to is that the market gets swamped with new bladesteels treated with half-baked heattreat protocols with no consideration for their applicability because everybody wants the next wondersteel....

Sorry, Nozh for going off on you like that. It is really nothing personal. I love many of your threads, and admire you for your willingness to play around with so many steels. But to call any steel "D2 on steroids" based on the chemical makeup I find hardly helpful and a bit far fetched.

Ok rant-mode off.

I am a steel "enthusiast" myself, but I rather wait till someone like Spyderco or WH or Fallkniven has tried a steel in a few knives before I get all excited. Heck even Sal waits till a steel has been in circulation for a while, before he forms a firm opinion.

Cliff Stamp · May 3, 2006

HoB said:
You have no clue what is going on in that steel on a structural basis. For all you know, that amount of Mo and the added W might change the properties such that it resembles in no way D2.

Since it is a high speed stainless it is very different than D2 which is neither stainless nor intended for high heat applications. It would be more similar to D5 which has 3% Cobalt to enable better hardness at high tempers or D7 which has a much higher wear resistance than D2.

But to call any steel "D2 on steroids" based on the chemical makeup I find hardly helpful and a bit far fetched.

He has used it, and was likely commenting mainly on the large increase in wear resistance due to the carbon/alloy carbide increase over BG-42. There is a lot of emphasis on this as the focus of knife performance, many people even equate it to edge retention, Catra does for example.

It would be difficult to predict behavior in other areas, for reasons you noted, the complex behavior of the intermixing of high alloys in general. I would like to see the torsional strength/toughness and compression strength data, plus wear resistance and carbide / grain size.

Problem though even if you have this, getting the exact heat treatment details from makers/manufactures to use that data is rarely possible.

-Cliff

nozh2002 · May 3, 2006

HoB said:
Mmmh, while I am sure you can get some hints from the composition, I don't understand how you can possibly say: "Hey, this must be a good blade steel"...or even worse "hey, this must be a better/similar bladesteel than D2/BG42" by simply looking at the composition? This can only lead to hype and hysteria. You have no clue what is going on in that steel on a structural basis. For all you know, that amount of Mo and the added W might change the properties such that it resembles in no way D2.

With all due respect but the statement alone that BG-42 "does not look so cool" underlines just how questionable the entire thread is. There are many very knowledgable people (like Sal just to name one) who hold BG-42 in very high regard (asside from the fact that it is supposed be difficult to heat treat). To dismiss BG-42 or any bladesteel based on its composition is just plain madness. For crying out loud, would you have figured INFI to perform as it does, based on its composition? The affects of Kr for example are mostly uninvestigated.

I mean, sure you can tell a tool steel from a HC steel from a basic stainless steel....but we are talking about highly alloyed and complex steels here. Metalurgy is more an art than a science (guidelines vs. strict predictability)! As the this thread clearly points out, you can not even tell how corrosion resistant that steel will be (though it meets the definition of a "stainless steel"), based on its chemical composition. How can you possible try deduce any more complex properies by simply looking at the composition?

All this leads to is that the market gets swamped with new bladesteels treated with half-baked heattreat protocols with no consideration for their applicability because everybody wants the next wondersteel....

Sorry, Nozh for going off on you like that. It is really nothing personal. I love many of your threads, and admire you for your willingness to play around with so many steels. But to call any steel "D2 on steroids" based on the chemical makeup I find hardly helpful and a bit far fetched.

Ok rant-mode off.

I am a steel "enthusiast" myself, but I rather wait till someone like Spyderco or WH or Fallkniven has tried a steel in a few knives before I get all excited. Heck even Sal waits till a steel has been in circulation for a while, before he forms a firm opinion.

Well, this is not random mix by somebody - this is result of japanese powder metallurgy, so I may expect that this something very cool. It is already used in kitchen knives succesfully I assume and Bosen Enkuto also show great performance - this is kind of context of my statements. Of course out of this context it may looks "questionable". But based on my experience with both steel - it does looks cooler then BG-42 to me, sorry. It does not mean that BG-42 is bad or something, it just mean that SRS-15 looks better. And this is not scientific congress or something this is BladeForum and bit overenthusiastic wording like D2 on steroids you may see around a lot.

And G-Sakai as I may presume very well may be one who doing knives for "someone like Spyderco". So no need to wait for Spyderco on my opinion.

This one looks like ZDP-189 for big knives. High speed steel suitable for high speed steel cutting probably will be tough. I am very enthusiastic about this one - hope Sal will find this one cool also - let see.

Thanks, Vassili.

HoB · May 4, 2006

Vassili, I appologize for my harsh words, I guess it reads harsher than I intended it. However, this is exactly my point: This is not a science convention, so how can you say based on the chemical make up that one looks better than the other....there is nothing to see here. All a statement like this does is helping a company to sell a steel with a funky make-up with no consideration of performance. Next thing you know a company with a clever marketing strategy is selling knives with a steel that has a chemical composition that "looks good".... maybe because it has 5% carbon or 10% Krypton or 50% Uranium. I am exaggerating of course, but I try to make my point clear.

So if SRS-15 is a great steel, that is just fine. As I said I am always ready to try something new, but why the need to compare it to some existing bladesteel based on its composition? This invokes the assumption that their properties will be comparable as well...but do your really know that? What is the toughness or hardness or wear resistance (just for starters) for example in comparison to D2? You said, it is D2 on steroids, so I assume that it will exceed D2 in some or all of these properties (without being inferior in any of those)...but do you actually have any data that supports that? And I don't necessarily mean some scientific data...as you point out, this isn't a science fair. Do you have for example personal experience with both steels and have compared them against each other, or know of someone that you trust, that has? I would very much like to read about personal experience, testing, technical data...anything that has more practical applicability than chemical composition.