# R2 steel and edge retention



## Veitsi (Jul 22, 2015)

Hi,

I am brand new to Japanese steels, and bought 2 knives from Takamura Migaki R2 steel - the 210mm and 130mm.
They are very nice and certainly sharper than any cheaper knives I have used (except ceramic, but they are so damn fragile).
The petty is very sharp and has a nice edge. However out of the box the gyuto had a few little 'micro teeth' towards the heel. After a few light uses there are more of these little serrations along the blade. Is this something to do with the 'powdered' construction of the steel? Am I just not using it correctly? I have experimented with push and rock cutting. Time to time I know I have accidentally given a bit of lateral movement on the board which doesn't sound good. Is it from that?
I also know I need to get a good wood cutting board - currently traveling so just have a cheap plastic thing right now...

I have yet to get sharpening equipment for these and no doubt these bumps will sharpen out once I get the hang of it (on a different knife first!). Any suggestions for sharpening stones for these, and best angles?

Thanks for any advice!


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## aboynamedsuita (Jul 22, 2015)

The board may be the culprit, also possibly your cutting technique. I have the 150 petty and 180 gyuto from the same series (good knives), and a bunch from the others too, and haven't had that issue. I have a hinoki board, but end grain maple, walnut and cherry are also frequently recommended




Welcome to KKF


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## aboynamedsuita (Jul 22, 2015)

Saw the part about sharpening stone recommendations. I have the Chosera stones, but there are many other options available depending on your budget and location.


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## IndoorOutdoorCook (Jul 22, 2015)

I wouldn't rely on out of the box edge. I always put on my own edge. New, used, whatever.


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## chinacats (Jul 22, 2015)

Often the initial edge has some poor steel leftover from the process. A single or possibly two sharpenings should take care of this as you get to 'fresh' steel.


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## aboynamedsuita (Jul 22, 2015)

IndoorOutdoorCook said:


> I wouldn't rely on out of the box edge. I always put on my own edge. New, used, whatever.



Keep in mind the OP is new to Japanese steels and (by the sounds of it) sharpening too. IME (which is limited compared to some of the pros here) Takamuras come with a good edge, but the chipping described sounds strange for a new knife OOTB.

As for sharpening, MTC Kitchen has YouTube videos from when they had the Takamura brothers in NYC for the Star Chefs ICC doing a "sharpening Takamura knives" video IIRC. You should also check out JKI (Japanese Knife Imports) YouTube videos as they are comprehensive and always get recommended.


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## James (Jul 22, 2015)

chinacats said:


> Often the initial edge has some poor steel leftover from the process. A single or possibly two sharpenings should take care of this as you get to 'fresh' steel.



+1


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## Krakorak (Jul 23, 2015)

chinacats said:


> Often the initial edge has some poor steel leftover from the process. A single or possibly two sharpenings should take care of this as you get to 'fresh' steel.



And putting of a microbevel at the end of the sharpening could be quite useful as well - here is an example which difference it may cause (OK, its in German, but there are enough pictures for comparing - look also at the bottom where an update with pictures AFTER this process is located) in basically the same knife as you have...
http://www.messerforum.net/showthread.php?128196-Review-ASAGAO-Gyuto-210-R2


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## ThEoRy (Jul 23, 2015)

Ceramic is not sharper than steel per se. They can both be ridiculously sharp. Steel is easier to maintain however.


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## Ruso (Jul 23, 2015)

I have Takamura R2 and the edge was little bit chippy at the beginning. Edge retention on his knives is very good in my book.


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## icanhaschzbrgr (Jul 23, 2015)

There was a thread somewhere about OOTB (out of the box) edges on Takamura R2 knives. It's not a fault of your technique, nor a fault of cutting board, it's just a fault of Takamura's factory sharpening. Once you sharpen knives and grind away OOTB edge, the problem will get away. 

Here's a picture of Takamura R2 OOTB edge after cutting one baguette.


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## Veitsi (Jul 23, 2015)

Ok, :IMOK:So it seems my best option is to sharpen it and assume it's just an OOTB issue. Icanhaschzbrgr, that's the kind of thing mine has, thought ones not as bad! So yours was fine after sharpening? My petty is perfect, no chips at all.

Nobody thinks this is a one off manufacturing/steel issue that warrants an exchange?

Thanks for the links to sharpening videos etc!

I tried uploading a picture but could see where- the picture icon just asked for a URL.


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## James (Jul 24, 2015)

Nope; happens to a lot of knives. Just sharpen it up and you'll be good to go!


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## chinacats (Jul 24, 2015)

James said:


> Nope; happens to a lot of knives. Just sharpen it up and you'll be good to go!




+1 Assume that all new knives need to be sharpened either by you or the vendor to get to the good stuff.


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## richard (Jul 24, 2015)

icanhaschzbrgr said:


> Here's a picture of Takamura R2 OOTB edge after cutting one baguette.


I remember way back on KF threads that some users were reporting chipped edges on PM knives with thin, polished edges on hard crusty breads, so I've personally avoided that myself by using non-PM knives or a scalloped/serrated edge knife on bread. Anyone else have experiences with these kind of knives and hard, crusty bread?


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## Knifefan (Jul 24, 2015)

icanhaschzbrgr said:


> Here's a picture of Takamura R2 OOTB edge after cutting one baguette.



R2 steel has a very similar chemical composition to SG2. That's not how a well sharpened and properly heat treated edge should look after cutting one baguette. I have several knives made of PM steel, including SG2, and have used them for cutting baguettes. None have chipped. The reason could be improper deburring, so that chipping occurs on the burr. If so, the issue should go away after putting the knife on a stone and forming a new edge without burr. Alternatively, but less likely, it could be a fragile edge created by overheating during the sharpening process. Also here, the issue should go away after removing metal from the edge. If not, then it could indeed be a heat treatment issue, which definitely would warrant an exchange.

Anyhow, a knife should not be supplied with an OOTB edge like this. If you bought this in a store next to you, I would actually change them or get them sharpened. If that's not an option, trying sharpening first is probably less troublesome than an exchange.


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## icanhaschzbrgr (Jul 24, 2015)

After first sharpening I haven't experienced chipping on the edge of that knife, so for me it definitely was OOTB edge issue.


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## Ruso (Jul 24, 2015)

> R2 steel has a very similar chemical composition to SG2.


AFAIK SG2 and R2 are exactly the same. Just two different names due to place of origin. There is a thread in KKF explaining it in more details.


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## MadDurrr (Jul 24, 2015)

Was it a fairly crusty and hard baguette? I've read that coarse exteriors can cause this pretty easily on really thin knives.


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## icanhaschzbrgr (Jul 24, 2015)

MadDurrr said:


> Was it a fairly crusty and hard baguette? I've read that coarse exteriors can cause this pretty easily on really thin knives.



Not that crusty. I have a tojiro serrated knife for a really bad ass baguettes, but any other from my knives can cut baguettes without chipping. In the thread that I mentioned earlier (it was on another forum actually) we came to conclusion that most probably the source of the problem was an overheated fragile OOTB edge. I wasn't the only one who experienced chipping of OOTB edge, and other guys weren't cutting baguettes, so it's not the type of food that caused problem.


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## Benuser (Jul 24, 2015)

With the OTB edge of a Blazen SG2 I had some microchipping as well, just as with most brand new blades. But unlike the poster with our German counterparts I wouldn't think about removing a factory edge with a Chosera 3k. I want to remove a bit of weak steel and use a Chosera 800 and after that only lightly strop and deburr, and put a rather conservative edge on it. I like both the steel's bite and edge retention. I want to reveal and enhance these properties, not undermine them.


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## aboynamedsuita (Jul 24, 2015)

richard said:


> I remember way back on KF threads that some users were reporting chipped edges on PM knives with thin, polished edges on hard crusty breads, so I've personally avoided that myself by using non-PM knives or a scalloped/serrated edge knife on bread. Anyone else have experiences with these kind of knives and hard, crusty bread?





MadDurrr said:


> Was it a fairly crusty and hard baguette? I've read that coarse exteriors can cause this pretty easily on really thin knives.





icanhaschzbrgr said:


> Not that crusty. I have a tojiro serrated knife for a really bad ass baguettes, but any other from my knives can cut baguettes without chipping. In the thread that I mentioned earlier (it was on another forum actually) we came to conclusion that most probably the source of the problem was an overheated fragile OOTB edge. I wasn't the only one who experienced chipping of OOTB edge, and other guys weren't cutting baguettes, so it's not the type of food that caused problem.



I remember Gator has something about the crusty breads on his review of the Miyabi 5000MCD Birchwood Suji IIRC

EDIT at zknives


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## richard (Jul 24, 2015)

Ruso said:


> AFAIK SG2 and R2 are exactly the same.


Yes SG2 and R2 are the same steel.
http://www.zknives.com/knives/steels/steelgraph.php?nm=sg2
A PM steel that where it is very similar to SG2/R2 is SRS-15
http://zknives.com/knives/steels/steelgraph.php?nm=SRS-15,SG2


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## WingKKF (Jul 24, 2015)

Most stainless and semi-stainless steels have poorer edge stability compared to carbon steels. There is no free lunch. What you gain in stain resistance, edge retention is lost in edge stability. There will be some who would argue otherwise but they're wrong :>. This is why carbon steels knives still exist.


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## salmonkiller (Jul 24, 2015)

WingKKF said:


> Most stainless and semi-stainless steels have poorer edge stability compared to carbon steels. There is no free lunch. What you gain in stain resistance, edge retention is lost in edge stability. There will be some who would argue otherwise but they're wrong :>. This is why carbon steels knives still exist.


Please enlighten me with a specific example...
Thank you


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## Benuser (Jul 25, 2015)

WingKKF said:


> Most stainless and semi-stainless steels have poorer edge stability compared to carbon steels. There is no free lunch. What you gain in stain resistance, edge retention is lost in edge stability. There will be some who would argue otherwise but they're wrong :>. This is why carbon steels knives still exist.


As always, it depends.
What you lose in edge stability you may win in corrosion and abrasion resistance.


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## Ruso (Jul 25, 2015)

WingKKF said:


> Most stainless and semi-stainless steels have poorer edge stability compared to carbon steels. There is no free lunch. What you gain in stain resistance, edge retention is lost in edge stability. There will be some who would argue otherwise but they're wrong :>. This is why carbon steels knives still exist.


Based on Devin Thomas data from http://www.kitchenknifeforums.com/showthread.php/4772-what-steels-and-why










Carbon edge stability is better on average compared to stainless, but the best mark was given to Stainless. Just something to think about.


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## WingKKF (Jul 25, 2015)

Yup and apparently AEB-L can only get to that state if it undergoes Devin Thomas's special heat treatment process. It seems AEB-L as done by other manufacturers (which is to remain unnamed) are nothing special. Here's some pictures to show why chromium carbides are generally bad for edge stability: http://www.hypefreeblades.com/files/schneiden.pdf . The big white stuff are chromium carbides. Except in the case of AEB-L they are large, wear resistant and have a tendency to tear away from the rest of the steel matrix when worn.

https://www.dictum.com/en/expert-knowledge/steel-for-cutting-tools#s61


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## chinacats (Jul 25, 2015)

Ruso said:


> Based on Devin Thomas data from http://www.kitchenknifeforums.com/showthread.php/4772-what-steels-and-why
> 
> 
> 
> ...



Nothing to think about...in addition to this being a subjective rating, stain resistance is weighted into the final score...of course a stainless knife wins...


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## Benuser (Jul 25, 2015)

chinacats said:


> Nothing to think about...in addition to this being a subjective rating, stain resistance is weighted into the final score...of course a stainless knife wins...



It's no subjective rating. The number reflects the -- relative -- 
position of a steel amongst a great number of other ones.


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## Benuser (Jul 25, 2015)

but the overall rating doesn't mean that much IMHO


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## labor of love (Jul 25, 2015)

Ruso said:


> Based on Devin Thomas data from http://www.kitchenknifeforums.com/showthread.php/4772-what-steels-and-why
> 
> 
> 
> ...



I wouldn't pay much attention to those charts. They seem biased and also lots of people have had very different conclusions after using knives from of those steels.


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## salmonkiller (Jul 26, 2015)

labor of love said:


> I wouldn't pay much attention to those charts. They seem biased and also lots of people have had very different conclusions after using knives from of those steels.


There are Better Stainless steels currently available than the ones used for this subjective comparison chart.Elmax ,S35VN and CTX-XPH, ETC.......


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## Ruso (Jul 26, 2015)

chinacats said:


> Nothing to think about...in addition to this being a subjective rating, stain resistance is weighted into the final score...of course a stainless knife wins...



I just put it their for Edge Stability purposes, nothing else nothing more.



labor of love said:


> I wouldn't pay much attention to those charts. They seem biased and also lots of people have had very different conclusions after using knives from of those steels.



At least it is some hard data from a reputable blade smith. I did not see any other similar comparison. If you find/have something please share.


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## Veitsi (Aug 5, 2015)

So after all the advice, I finally went to a real pro sharpener here in Sydney at ChefsArmoury, and he fixed up the edge, and put a slightly less steep angle on it. He said it has been a common problem with the Takamura R2 range OOTB.

Thanks for all the advice


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## richard (Aug 5, 2015)

Glad the Takamura is working out for you!


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## DevinT (Aug 5, 2015)

Ruso said:


> I just put it their for Edge Stability purposes, nothing else nothing more.
> 
> 
> 
> At least it is some hard data from a reputable blade smith. I did not see any other similar comparison. If you find/have something please share.



We based the numbers in the chart on grain size, carbide size, carbide volume and stain resistance. The numbers are also based on a steels potential when properly heat treated. 

There are lots of steels not included in the chart and there are many other factors that will influence a knife's ability to hold an edge. 

For all cutlery, the finer the grain, the finer the carbide, the harder the carbide, and the amount of carbide will make a blade hold an edge longer.

A well known cutlery company tested two pieces of steel with the same chemical composition made by two different companies in two different countries. They heat treated them the same and tested the edge holding ability on a CATRA testing machine. The results were very different.

R-2 is a steel with medium small carbides and a large carbide volume. It should be a very good steel for knives. The smaller the carbide the smaller the sharpening angle that can be used.

Hoss


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## Benuser (Aug 5, 2015)

Thank you for your clarification, Hoss. Now, for the CATRA enigma: could different iron ore explain the diverging results?


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## DevinT (Aug 6, 2015)

Probably due to impurities and pour mill practice leaving the steel in a phase/condition that is not optimum for best heat treat response.

Hoss


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## Benuser (Aug 6, 2015)

thanks, Hoss


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