R2/SGR2 knives: edge retention and sharpness

I am thinking about getting an R2/SG2 knives. What I've heard is that these knives have very good edge retention. However, I have also heard that it is not always easy to get them very sharp (like AEB-L, for example). It appears pieces easily break from the edge when sharpening.

Can anybody tell me about their experiences with R2/SG2 and particulary edge retention and the ability to get them sharp (like, for example, AEB-B)?

Had Takamura gyuto in R2 and can't say it's any harder to sharpen than AEBL. It feels more wear resistant and just takes more time on the stones, but nothing extreme. I'd say there are knives that could take sharper edge in my collection, but for the kitchen needs the differences are irrelevant.
I gave my Takamura to my parents a year or two ago and it keeps edge longer than their other knives in A2 and VG10.

I'm a pretty inexperienced sharpener. I don't find R2 (or for that matter SRS15) difficult to sharpen or deburr. Certainly not quite as easy as shirogami or even aogami but not difficult. Much easier to deburr than Western stainless IME. I can't comment on AEBL but I would say that it's if anything easier to deburr than my Fujiwarra Kanefusas which I think are AUS8.

With my meagre sharpening skills, I can detect a difference between AUS8 and R2 in general kitchen use. I can get carbon a bit more hair splitting sharp than R2 but it doesn't strike me as making much difference in the kitchen.

I've never had problems with R2 chipping in general home kitchen use. Edge retention is great, certainly superior to any non honyaki carbon that I've used.

Keep in mind that while the steel's chemistry is important to the sharpening characteristics, the HT is at least as important, so not all R2 knives are created equal. Make sure you buy from a reputable maker who knows how to HT the steel well.

Can you say which knife you are looking at?

Basically what Nemo said. I have an Itou and Ryusen Blazen in R2/SG2 (Also have a tristone almost finished so cant wait to compare the them).

I have no dramas sharpening it. Yes it takes longer than white 2 (30 seconds per side as opposed to 15, using jki diamond set).

But I think it takes a screaming edge and keeps 80 to 90% of that edge for ages.

And I give that it is easier to sharpen than my aritsugu a type or even my ealy carbon damascus (01 and L6, if my memory is correct).

I have a Dalman in aeb-l which sharpens very easily, carbon-like (using an aoto muddy stone only); the Tanaka (in R2/SG2) takes more effort to sharpen, but it's still sharpens easy, specially on synthetic stones. Both have good retention for a home cook like me.

@icanhaschzbrgr how do they have an A2 (as in A2 tool steel) knife unless they are knife geeks too - or do you mean Aogami 2?

LifeByA1000Cuts said:

@icanhaschzbrgr how do they have an A2 (as in A2 tool steel) knife unless they are knife geeks too - or do you mean Aogami 2?

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I have hard times selling knives, so once I really need more room for new knives, I dump some of my collection to parents or relatives. That's how they could end up with Marko Tsourkan gyuto in A2 and some other pretty fancy knives.

I have a Takamure Hana which I've sharpened a lot, gets stinky sharp and stays that way for a long long time. I've got a few others in R2 but haven't sharpened them much - not much use (too many knives) combined with long long edge holding.
A fabulous steel for kitchen knives, well I like it.
May take a bit longer to sharpen, but nothing noticeable.
I have a variety of carbon knives, single and double bevel, and for my mind I can get the Takamura as sharp as any, though not sure how I'd measure

I am a fan of SG2, and at a previous thread concerning similar issue I asked the members participating there about a comparison between SRS15 and SG2, and one member stated that SG2 becomes a little sharper.

I'm convinced by you guys that it has a very good edge retention. And with my Wicked Edge it won't be much more difficult to sharpen than very hard steels. But can I assume that R2/SG2 gets (nearly) as sharp as AEB-L? That's my main remaining question and important to me.

I can't tell about AEBL, but gets equally sharp to white 2, so it is top

I suspect that if you are planning to shave with it, AEBL could be made a little sharper (assuming you are a good enough sharpener, which I am not). OTOH, if you are planning to cut food with it, the difference is not significant.

From my limited experience with R2/SG2 I would say it's an other kind of sharpness, more aggressive if I may say so, that gets lost quickly. The sharpness that remains is plenty sufficient for common kitchen work, though. AEB-L has a smoother sharpness that recalls carbon, and a more even dulling curve.

@Benuser so would you still invoke the "stainless, so 5000 and call it a day" rule on AEB-L if you wanted a push cut/fine slicer edge, or more go the "grits to infinity" route as for carbon?

With AEB-L go as far as you like. With R2/SG2 I see no benefits to go that fine except for deburring.

Benuser said:

From my limited experience with R2/SG2 I would say it's an other kind of sharpness, more aggressive if I may say so, that gets lost quickly. The sharpness that remains is plenty sufficient for common kitchen work, though. AEB-L has a smoother sharpness that recalls carbon, and a more even dulling curve.

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Ben, if R2/SG2 looses its sharpness quicker than AEB-L, even though it is plenty sufficient for kitchen work, how come it has the name that R2/SG2 has a long edge retention. Or doesn't it?

I didn't mean to say R2/SG2 has the lesser edge retention when compared to AEB-L. The dulling curve is different, i.e. more abrupt.
AEB-L is not specially known for it's edge retention. As far as I can see R2/SG2 keeps a very usable edge for a very, very long time. But it's remarkable initial sharpness gets lost quite quickly, IIRC.

For food use I can't really tell there is a significant sharpness difference between R2 and AEB-L. I can tell R2 can get noticeably sharper than VG10 or other Japanese moly stainless. R2 is great stuff, and I highly recommend trying it.

Yep same here with SG2/R2 they keep the insane sharpness longer than my Ashi Stainless knifes. My SRS15 PM is even cooler. Actually both steels are great since i hate patina and its super easy to give them a touch up.
I think my Sg2 stuff has not the maximum scary sharpness that it can get (because i suck at free sharpening and will be bogdanised this week).. But its sick how long its still cutting very good.

But really touchup take just some strokes on both steels and i would be sad if i couldnt use all the brickwall full of stones

"I didn't mean to say R2/SG2 has the lesser edge retention when compared to AEB-L. The dulling curve is different, i.e. more abrupt.
AEB-L is not specially known for it's edge retention. As far as I can see R2/SG2 keeps a very usable edge for a very, very long time. But it's remarkable initial sharpness gets lost quite quickly, IIRC."

Sounds very much like comparing blue vs white carbon?

Is understanding AEB-L as a "420B for grownups" far off the mark? How is the dry-strop response (for comparison, I'd consider shirogami extremely stroppable, VG10, ZDP and blue#number in the middle, R2 not-quite sure, AS horrible)?

@Krassi I bet you outsharpen a lot of people on here, and that is probably what you want to hear (and which doesn't change a thing about it probably being the truth).

in my experience, r2 will vastly outlast any other stainless (non pm) edge retention, by and large. I only have used tanakas and kurosakis renditions of the steel, and while I prefer tanakas knives, they both sharpen fairly easily, and they stay very sharp for ever

I've sharpened coworkers sg2/r2 blades for them. Never actually used the knives themselves but I can say that the knives took pretty remarkable edges easily as far as the spectrum of stainless goes. Personally I'd prob rather own whatever stainless sharpens the easiest (I'm guessing ginsanko, aebl, swed stainless, or semi). Tanaka r2 is really nice.

Man, those new blazens that jki carries really look nice, splendid looking grinds. Also Tanaka is classic, and kurosaki look like fun. Lots of great blades seem to be made w sg2. I must say I would be very interested in reading whatever future review mark76 writes concerning whichever sg2 knife he decides on.

My 150 WS SG2 Kramer utility gets insanely sharp and holds it a long time. Dry stropping works. The steel is ideal for kitchen use. Have to be careful not to over polish the edge. Me likey

I have 5 R2 knives, and had 2 (presumed AEB-L) knives. R2 is superior in my mind. its edge retention is comparable to AS. but the 2 AS knives i have are particularly known for their edge retention, so against lower hrc AS R2 may last longer..
Dont forget to mention edge angle, and HT. But generally I find R2 to be fantastic, and the maker tries to not mess it up. as opposed to white, where it starts off a a generic carbon and the maker tries to make it into a fantastic blade. all of my R2 blades (Itou,takamura(x3), Zkramer outlast my white steel knives (kono honyaki w2, muteki carter, teruyasu) in raw edge retention, though it can be argued acidity in food plays a large factor in that.

I don't think it's the acidity. White is a very pure and simple steel, known to get incredible sharp, and ease of sharpening, but not for high edge retention.

richard said:

I don't think it's the acidity. White is a very pure and simple steel, known to get incredible sharp, and ease of sharpening, but not for high edge retention.

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Don't want to disagree but acidity/corrosion plays a large part imo. I have noticed with my carbon bladed I lose sharpness between uses (I am home cook that stores knives in a knife block and rotates through them randomly).

My only conclusion is corrosion, likely aided by food acidity.

I am not talking significant corrosion. But it is very easy for corrosion to occur at a micro scale at the edge and effect sharpness.

malexthekid said:

Don't want to disagree but acidity/corrosion plays a large part imo. I have noticed with my carbon bladed I lose sharpness between uses (I am home cook that stores knives in a knife block and rotates through them randomly).

My only conclusion is corrosion, likely aided by food acidity.

I am not talking significant corrosion. But it is very easy for corrosion to occur at a micro scale at the edge and effect sharpness.

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Just some temperature and humidity changes cause some dulling, probably micro-corrosion, especially but not only with carbons, you may easily deal with by a few strokes on newspaper, rough leather, denim or whatever you have. No big deal, but it does occur.

Yeah not saying its hard to deal with... it is now why i keep my loaded felt strop and takenoko at the base of my knife block, rather than with my sharpening gear... so they are handy for the quick touch ups

Benuser said:

With AEB-L go as far as you like. With R2/SG2 I see no benefits to go that fine except for deburring.

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SG2 is also very fine grained. I have stripped it up to 0.25 microns, and the edge improves all the time.
After 0.25 microns, maybe my finer is 0.05 I don't remember exactly now, but after the finest, it cuts as if it cuts air, no resistance , doesn't slip