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View Full Version : Edge Retention Vs Ease of Sharpening



Marko Tsourkan
09-05-2011, 01:21 PM
I decided to post it here, as it is pretty relevant to most folks on the forum, pros and home cooks.

There is an inverse relationship between edge retention (or steel's wear resistance) and ease of sharpening. More wear resistance in a knife is likely to result in a more time on stones and perhaps even in a new set of stones that are more suitable for such a task (Shapton, Sigma, diamond plates, etc).

For pros time is money, so exceptional edge retention might be way to go, but for home cooks, I am not sure, particularly if it comes at a cost and not with an immediate benefit.

Curios what other think about this.

M

PS: Just realized I am over 1000 posts. :)

stevenStefano
09-05-2011, 01:44 PM
If I had a choice I'd go for edge retention every time. I have knives that are seen as easy to sharpen and some that are seen as harder to sharpen. To me it doesn't seem to take much longer for the harder to sharpen knives, maybe half an hour which means little to me. I'd rather spend a little more time on the stones for a knife that holds an edge longer

Marko Tsourkan
09-05-2011, 01:46 PM
So, I probably should ask what is the average edge retention on most knives for home cooks (with stropping, but not touching up on stones or rods)?
A week, two weeks, a month?

M

Eamon Burke
09-05-2011, 01:53 PM
Honestly, even at home, I prefer a steel that is a bastard to sharpen and stays faithful for a long time. For work, I would say a long time is 2 weeks, cheapo knives like Forschners don't make it through 3 days. VG-10 lasts about 5 days, it *might* make it through the week.

I've also sharpened some knives, notably a recent Wusthof, that was a huge pain to sharpen--took forever to work out tiny chips in the edge, which I was doing on a 120grit stone, because they were so small I figured it'd be real quick. It took about 25 minutes to get them out, and I really doubt that it would stay sharp for very long, judging by it's price and construction quality. Not sure why it was such a pain to sharpen, but it got me thinking.

oivind_dahle
09-05-2011, 01:53 PM
Edge Retention :)
L6 anyone?

Cadillac J
09-05-2011, 01:54 PM
Maybe I am the odd man out, but I've not had a knife/steel in regular sharpening(not thinning/reprofiling) that I found was significantly harder to sharpen than others. Of course steels like white#2 have a smoother and more refined feel on the stones and are easier to deburr, but some of my best retention knives in AS and semi-stainless tool steels really sharpen as easy as anything else.

Eamon Burke
09-05-2011, 01:57 PM
Maybe I am the odd man out, but I've not had a knife/steel in regular sharpening(not thinning/reprofiling) that I found was significantly harder to sharpen than others. Of course steels like white#2 have a smoother and more refined feel on the stones and are easier to deburr, but some of my best retention knives in AS and semi-stainless tool steels really sharpen as easy as anything else.

Aren't your knives exclusively <13% Chromium? There are a few stainless steels that I've sharpened that make you work MUUUUCH harder to get the same edge out of them, though once it's there, it performs well.

Cadillac J
09-05-2011, 01:59 PM
So, I probably should ask what is the average edge retention on most knives for home cooks (with stropping, but not touching up on stones or rods)?
A week, two weeks, a month?

As a home cook, my edges are immaculate at all times. I have a sick need for that fresh edge, so I strop pretty much after every use and probably put to a high grit stone each month, even though the blade is still cutting really well. I'd imagine my edges could go a few months easily with just stropping...but I'd miss that ultimate feeling.

Marko Tsourkan
09-05-2011, 02:06 PM
Alloys in a steel, manipulation during heat treatment, final hardness of over 60RC combined can result in an edge that is very difficult to sharpen. I am sure it won't feel like it on diamond plates, but on regular aluminum oxide stones, it will require a lot of time and sweating, as I discovered yesterday, to get a knife relatively sharp (nothing like 52100 sharp though!).

Very interesting, keep the discussion going. :)

M

Vertigo
09-05-2011, 02:07 PM
I honestly prefer knives that are a breeze to sharpen, nothing in the world irritates me more than fussy steel and burrs that won't give up. If that means having to sharpen a little more often, I don't mind--at least it's quick and painless to do. I cut a ton of acidic foods at work, something like 6-8 gallons of salsa fresca a day plus heaps of citrus and onions, and it turns my carbon edges to mush in no time at all. Rather deal with that, though, than have to sit there begging and pleading with a chunk of VG-10 that refuses to cooperate.

Cadillac J
09-05-2011, 02:11 PM
Aren't your knives exclusively <13% Chromium? There are a few stainless steels that I've sharpened that make you work MUUUUCH harder to get the same edge out of them, though once it's there, it performs well.

Correct me if I'm wrong, but aren't most of the knives we talk about <13% Chromium? I just assumed Marko was referring to characteristics of most of the knives we discuss on a regular basis.

I remember hearing horror stories about sharpening Globals, but didn't think they were an issue. They don't have a great feel while grinding on the stones, but I wouldn't consider them difficult to get a really sharp edge on.

My point was that I, for a home cook, don't purchase a knife because of ease of sharpening nor for edge retention...just the combination of profile, geometry, edge taking, steel, etc.

Eamon Burke
09-05-2011, 02:26 PM
Correct me if I'm wrong, but aren't most of the knives we talk about <13% Chromium? I just assumed Marko was referring to characteristics of most of the knives we discuss on a regular basis.

I remember hearing horror stories about sharpening Globals, but didn't think they were an issue. They don't have a great feel while grinding on the stones, but I wouldn't consider them difficult to get a really sharp edge on.

My point was that I, for a home cook, don't purchase a knife because of ease of sharpening nor for edge retention...just the combination of profile, geometry, edge taking, steel, etc.

VG10, CPM154, Damasteel, the "Molybdenum Vanadium" so many are made from, are all >13% Chromium and therefore actually stainless. In a pro setting, stainless can be a huge thing, there are even ignorant health inspectors that don't allow carbon steels. I just did some in CPM154 what suuuuuuuuuucked to sharpen.

JMJones
09-05-2011, 03:01 PM
I much prefer ease of sharpening for my kitchen knives. I truly dislike stainless steels for this reason. With strop and a fine ceramic rod, I rarely need to go to the stones to resharpen. I find that it is just way easier maintaining an edge with a little care than to let the knife get truly dull before resharpening. Also as long as we are talking non stainless steel, I dont think a few points harder will be that big of a deal on the stones as long as the edge is somewhat maintained during use.

UglyJoe
09-05-2011, 04:49 PM
As a home cook I actually prefer a knife that gets dumb-sharp but doesn't hold an edge that well... it gives me an excuse to actually get to the stones more often, which I enjoy. If I were a pro I think I'd want things just about the opposite of how I like my home knives.

euphorbioid
09-05-2011, 04:54 PM
As a home cook I actually prefer a knife that gets dumb-sharp but doesn't hold an edge that well... it gives me an excuse to actually get to the stones more often, which I enjoy. If I were a pro I think I'd want things just about the opposite of how I like my home knives.

I agree wholeheartedly.

Vertigo
09-05-2011, 04:57 PM
I just did some in CPM154 what suuuuuuuuuucked to sharpen.
My Rodrigue is CPM-154, and it's the most enjoyable stainless I've sharpened. Takes no time or effort to get a burr going, and it falls away with little effort. A completely different world from something like VG-10 in a Shun. Might be a heat treat thing, but I just assumed because it was a powdered steel, it was a little more accommodating.

Cipcich
09-05-2011, 05:18 PM
I'm not sure that edge retention and ease of sharpening are always at odds, not am I sure that hardness necessarily makes a knife harder to sharpen.
One example I would cite is a Carter Funayuki of pretty hard White #1, which is easy to sharpen, and maintains its edge very well; certainly far better than most While #2 knives out there. Another would be Sadayusa knives, even harder, which are easy to sharpen to a very fine edge, and which never seem to get dull (they do get some microchips . .).
On the other hand, with the exception of a DT-ITK in AEB-L, stainless knives in my experience are not only no fun to sharpen, but get smooth real quick.

NO ChoP!
09-05-2011, 05:26 PM
Again, I think its different steels, different knives for different tasks; at least thats the excuse I use to obtain more and more knives! I have a virgin carbon Masamoto that takes the sharpest of edges, but seems to dull rather quickly; but, I can bring it right back within a couple of minutes on a mid grit stone, strop it a couple of times, and back in business. This is the knife I grab when I want something super sharp for a quick task.

On the other spectrum for me, is my Kono HD. It gets pretty sharp, and I can use it for days doing heavy prep, and it will retain its edge. But when it dulls, I need to put it through a progression of at least ten or fifteen minutes.

You are right, it's a trade off, no one being better than the other, just depends on the need.

jmforge
09-05-2011, 05:34 PM
I may be wrong, but I was under the impression that L6 is known for it's toughness, not its abrasion resistance or ability to take a "laser" edge for that matter. AEB-L by all accounts has very fine grain and can take a super keen edge, but doesn't have enough carbon to form any carbides worth mentioning.
Edge Retention :)
L6 anyone?

geezr
09-05-2011, 05:58 PM
As a home cook I actually prefer a knife that gets dumb-sharp but doesn't hold an edge that well... it gives me an excuse to actually get to the stones more often, which I enjoy. If I were a pro I think I'd want things just about the opposite of how I like my home knives.

nother - :plus1:

Larrin
09-05-2011, 06:23 PM
I may be wrong, but I was under the impression that L6 is known for it's toughness, not its abrasion resistance or ability to take a "laser" edge for that matter. AEB-L by all accounts has very fine grain and can take a super keen edge, but doesn't have enough carbon to form any carbides worth mentioning.
But to be fair neither do any of the commonly used carbon steels outside of Blue Super. Carbide volume is where we get to the real discussion of edge retention vs ease of sharpening. However, if it's true that most users around here are push cutting, extra carbide volume may not contribute to edge retention. Then there's a separate question of carbide hardness, i.e. there have been complaints of difficulty of sharpening of S30V, which has similar carbide volume to CPM-154 but is more difficult to sharpen because of the vanadium carbide.

Keith Neal
09-05-2011, 07:15 PM
As a home cook I actually prefer a knife that gets dumb-sharp but doesn't hold an edge that well... it gives me an excuse to actually get to the stones more often, which I enjoy. If I were a pro I think I'd want things just about the opposite of how I like my home knives.

Agree.

Eamon Burke
09-05-2011, 08:57 PM
there have been complaints of difficulty of sharpening of S30V, which has similar carbide volume to CPM-154 but is more difficult to sharpen because of the vanadium carbide.

That is for real. I tried to shine one up with wet/dry sandpaper, and the 220 grit, one pass, didn't even scratch it. What's that about?

tk59
09-05-2011, 10:13 PM
I like edge retention a lot. I can sharpen when I feel like it as opposed to trying to decide when I'm pissed off enough for the edge to "need" it. I don't like crazy burrs/wire edges but I haven't really had to do anything special to get rid of them, in general. (A-type, certain VG10, and a couple others take a little more work but not terrible...) There may be a point where more edge retention really isn't worth it. Many of the knives I like most, have very good edge retention but not crazy. The best thing about owning a high end knife is the first couple of hours of cutting straight off the stones. If I can get a few more hours off of a sharpening, that would be great. So far, it doesn't really seem to matter. I sharpen, I get an awesome couple of hours (depending on what I'm cutting) and then cutting is merely very nice, not awesome. I really just want the awesome. Basically, give me more edge retention but I don't want to sacrifice on sharpness (no huge carbides and no crazy burrs). Under a microscope, it is clear that ripping off crazy burrs leaves an ugly scar on your edge. (Yes, that one is for you, Salty.)

jaybett
09-06-2011, 02:31 AM
I don't know if home cooks, will ever be good judges of edge retention. I've got more knives, then I need. I rotate through a series of knives, so none of them really need to sharpened on a regular basis.

Jay

JohnnyChance
09-06-2011, 03:02 AM
I prefer edge retention. I love my Zwilling Kramer except for the fact that it does not have good edge retention. Especially in 52100 I would prefer something harder, even if that sacrifices ease-of-sharpening. The ZK appears to be sub 60 HRC, maybe as low as 57-58, and from other 52100 knives I have used in the 61-62 HRC range, I much prefer the harder 52100. They don't quite feel the same while sharpening, less responsive, but get just as sharp when you get the hang of it and the difference in edge retention is pretty significant.

so_sleepy
09-06-2011, 03:44 AM
I prefer edge retention. I love my Zwilling Kramer except for the fact that it does not have good edge retention. Especially in 52100 I would prefer something harder, even if that sacrifices ease-of-sharpening. The ZK appears to be sub 60 HRC, maybe as low as 57-58, and from other 52100 knives I have used in the 61-62 HRC range, I much prefer the harder 52100. They don't quite feel the same while sharpening, less responsive, but get just as sharp when you get the hang of it and the difference in edge retention is pretty significant.

The specs say the Z-Kramer is hardened to 61 HRC

JohnnyChance
09-06-2011, 03:54 AM
The specs say the Z-Kramer is hardened to 61 HRC

You are correct, that is the advertised HRC. I looked for it before and didn't see it. Feels way different than other 61 HRC 52100 I have used. Maybe the difference is in the heat treat procedure and not the final rockwell rating.

Larrin
09-06-2011, 12:40 PM
That is for real. I tried to shine one up with wet/dry sandpaper, and the 220 grit, one pass, didn't even scratch it. What's that about?
Vanadium carbide is harder than the abrasive.

Lefty
09-06-2011, 01:33 PM
For me, I'll take stupid sharpness, as long as it has good retention. I'm a home user, so I don't have to worry about getting through service, and I can always switch knives as I please.
Another thing is, sharpening is as much a part of the hobby as researching, tweaking, developing my technique, etc. If i have an excuse to sharpen, I'm a happy camper, as long as it isn't the same knife over and over again.

stevenStefano
09-06-2011, 01:40 PM
I am a a pro and unlike many people I basically see sharpening as a necessary function rather than really enjoying it. I have very little free time so edge retention is important to me. I find sharpening interesting because you always find ways to refine and hone your technique, but I wouldn't say I do it for fun or when I don't really have to.

bieniek
09-06-2011, 02:50 PM
Marko, do you ask because you want to figure out perfect compromise? Why wouldnt you do one serie for one group, and one for the other?

I myself like sharpening much, I do it as hobby and for money sometimes, i spent long long time over stones instead with my wife :D and I dont mind it.
So if I would posses a knife that would be a challenge for me in sharpening, but would give back great amount of service, then I would be the happiest.
But if I would have to do karate-gimmicks to keep it sharp and spend time over nothing, it would annoy my arse... And it would feel like Zwilling... or Sabatier...I just look at the rack and i choose something else to cut with, the whole pleasure of prep is gone with those knives somewhat, just because you expect something more out of the amount of work you put into it.
So the balance between amount of input and output is the key?

SpikeC
09-06-2011, 03:00 PM
Personally, I would think that a knife that worked for a pro kitchen would be fine for me. Retention is great for when you just want to get on with the cooking, and if you like to sharpen for the sake of sharpening there is no one who is standing behind you telling you to knock it off! Playing with subtle changes in the edge is always allowed and lets a person get out the stones whenever the mood strikes.

mpukas
09-06-2011, 11:05 PM
this


...The best thing about owning a high end knife is the first couple of hours of cutting straight off the stones. If I can get a few more hours off of a sharpening, that would be great. So far, it doesn't really seem to matter. I sharpen, I get an awesome couple of hours (depending on what I'm cutting) and then cutting is merely very nice, not awesome. I really just want the awesome. Basically, give me more edge retention but I don't want to sacrifice on sharpness...

and this


...I basically see sharpening as a necessary function {snip}. I have very little free time so edge retention is important to me. I find sharpening interesting because you always find ways to refine and hone your technique...

I'm a home cook and private chef (and primarily a self-employed over-worked, under-paid architect :tooth:). I want that awesome edge every time. Nothing is more annoying than grabbing a knife to prep dinner and the edge not being there. Or getting half way through a prep of a big dinner gig and feel the need to strop or hit the stick to get some semblance of awesome back.

I like how sharp and easy to get sharp white #2 is, but I like the retention of SG2 and AS.

Knifefan
09-08-2011, 12:45 AM
In terms of efficiency, clearly edge retention is preferable. One shouldn't only consider how many strokes you need to sharpen a knife, but also take into account the time needed for the preparation of one sharpening session on stones, including cleaning up etc. In my experience I need about 50% more strokes to sharpen ZDP-189 as compared to VG10, and VG10 needs about 50% more than steel in the HRC 57 category. The extra time needed for those few additional strokes is very little as compared to the total time needed for one sharpening session. Therefore if time matters, edge retention is the way to go.

I actually do like sharpening and it always a great feeling to produce that super sharp edge. But I don't have the time to do that too often. Thus I want edge retention.

Dave Martell
09-08-2011, 07:03 PM
I think that if I were a professional cook I'd look for a knife that offered the best edge retention possible BUT it would also need to be easily sharpenable - both in abrasion rate and deburring.

For the home cook I see this more of a matter of personal taste with regards to do you like to sharpen often or not. Needs will be based more on this preference than the actual need to maintain an edge forever.

olpappy
09-08-2011, 09:19 PM
As a home cook I don't think it makes much difference for me, if anything I kind of lean towards ease of sharpening, I have definitely noticed that certain knives can be a PITA, for example trying to flatten a yanagi with high RC hagane, or certain stainless which are more abrasion resistant (S30V). Since I'm at home it's not the same as being out in the field with a hunting knife and not wanting to carry sharpening gear.

A lot of people love their Sabatiers and the RC on those is advertised as 54-56..... some old Sabs probably outlived their previous owners by quite a bit, on the other hand some of the pro cooks here can use up/wear out even a harder steel blade pretty quickly.

AMP01
09-09-2011, 12:38 AM
So Dave, What knife -or- knives do you think offer(s) the best edge retention and is/are easily sharpenable? It is always nice to be able to as a guru !!! You have sharpened some of my knives ~ & when I got them back, they were screeeeming sharp like we wish all knives were all the time! :)

Cheers,

Andrew

Dave Martell
09-09-2011, 12:42 AM
So Dave, What knive do you think offers the best edge retention and is easily sharpenable?


I can't answer this one since my knowledge of edge retention on specific knives is all hearsay.

AMP01
09-09-2011, 12:45 AM
Out of the knives that you have used, which is easily sharpened and has great edge retention?

Cheers,

Andrew

Dave Martell
09-09-2011, 12:53 AM
This is a very small window we're looking through here Andrew. LOL :D

Eamon Burke
09-09-2011, 12:55 AM
Out of the knives that you have used, which is easily sharpened and has great edge retention?

Cheers,

Andrew

I think what he's saying is that he doesn't get the opportunity to put a knife through the paces at a job and wear it down, he is in the business of getting them optimally sharp and durable, and adjusting to how the customer wants it done/likes it/responds to it. Since he's just going by however other people like it, it's actually second-hand knowledge.


I will venture to say that while there are great stainless steels out there for SURE, the magic combo of edge retention/sharpenability is more often found in carbon steels.

AMP01
09-09-2011, 12:56 AM
But Dave, out of this small window, what do you see? :laugh:

AMP01
09-09-2011, 12:57 AM
johndoughy,

Out of the knives you have used, any insite to this magical combo of easy to sharpen and great edge retention?

Eamon Burke
09-09-2011, 01:06 AM
It's a trade-off. The factors that make a knife keep it's edge are the same as those that help it resist abrasion(sharpening). The makeup of a steel is a part of this, but the heat treat is a bigger part.

The trouble with stainless steel is managing the Chromium Carbides, which are stupid.

Sorry, it's very late for me and I've had many a long day this week, I'll defer to someone else with an alert mind and knowledge of metallurgy. Just know that a knife that gets crazy sharp, stays sharp forever, and needs only a quick brisk sharpening does not exist.

AMP01
09-09-2011, 01:10 AM
Awe c'mon,

I am just looking for the Holy GraiL of knives !!! :thumbsup2:

Eamon Burke
09-09-2011, 01:21 AM
Awe c'mon,

I am just looking for the Holy GraiL of knives !!! :thumbsup2:

Good news then! Find a guy who makes top-notch kitchen knives, heat treats his own stuff, is familiar with a steel you like. Communicate copiously, pay him well, and you will end up with a knife that will not leave you wanting.

Lefty
09-09-2011, 08:26 AM
I've been really pleased (as a home user) with S35VN. So impressed, that I've sent it out to a friend here who knows a thing or two about knives to give the steel a try, to either back up my claims, or tell me I'm nuts! Haha
It should be interesting to see what more people think of it, as it gets into more people's hands.
Was it a absolute breeze to sharpen? No, but it wasn't anywhere close to hard to sharpen, either. The retention should be way up there, but I won't say for sure until more of us try the steel, with a proper HT.

Eamon Burke
09-09-2011, 09:39 PM
I'd love to try a blade in s35vn at work, but don't have the scratch to buy one just to try.

Marko Tsourkan
09-09-2011, 09:42 PM
Do you use Aluminum Oxide stones to sharpen S35VN?

JBroida
09-09-2011, 09:45 PM
i have... works perfectly well... fast even

I have had no problems with this steel so far except that i dont like the edge feel

Lefty
09-10-2011, 12:47 AM
What is it that you don't like, Jon? I'm not challenging, just curious, that's all.
I've now used and sharpened two different S35VN blades and they're quite different animals.

tk59
09-10-2011, 01:08 AM
Does abrasion resistance necessarily correlate with difficulty to remove a wire edge/burr? It seems that some blades aren't particularly wear resistant but hold onto a burr (VG10) and others are more wear resistant but sharpening relatively easily (zdp-189). In either case, it really doesn't seem to take very long to develop a burr.

Just a few minutes ago, I sharpened three knives in identical fashion (as much as humanly possible): two from different makers in 52100 and a DT-mystery steel knife (purported to be even more wear resistant than 52100). I used a Beston 500 to develop a burr, Gesshin 1k (about 10 strokes per side), Gesshin 5k (about 20 strokes per side) and Naniwa SS 8k (about 20 strokes per side) plus 0.25 micron diamond on Dave's strop (~5 strokes per side). The one of the 52100 knives and the mystery steel knife got absolutely screaming sharp, but the third in 52100 took a bit more work on an 8k stone and strop to really get rid of the wire edge and still didn't seem quite as sharp.

JBroida
09-10-2011, 01:42 AM
so, i've tried a small pocket knife and the haslinger in s35vn... different, but the same feeling i didnt like of the edge... sharpening felt very sandy and the edge never got quite the sharpeness i was looking for... toothiness was nice, but the type of thoothiness it had wasnt what i was hoping for... if i had to discribe the feeling of the steel, the words flatt and dull(as in senses) come to mind.

As an example of a toothy steel i like, think D2.

Lefty
09-10-2011, 07:31 AM
Gotcha! Thanks Jon!

Larrin
09-10-2011, 09:28 AM
Does abrasion resistance necessarily correlate with difficulty to remove a wire edge/burr? It seems that some blades aren't particularly wear resistant but hold onto a burr (VG10) and others are more wear resistant but sharpening relatively easily (zdp-189). In either case, it really doesn't seem to take very long to develop a burr.

Just a few minutes ago, I sharpened three knives in identical fashion (as much as humanly possible): two from different makers in 52100 and a DT-mystery steel knife (purported to be even more wear resistant than 52100). I used a Beston 500 to develop a burr, Gesshin 1k (about 10 strokes per side), Gesshin 5k (about 20 strokes per side) and Naniwa SS 8k (about 20 strokes per side) plus 0.25 micron diamond on Dave's strop (~5 strokes per side). The one of the 52100 knives and the mystery steel knife got absolutely screaming sharp, but the third in 52100 took a bit more work on an 8k stone and strop to really get rid of the wire edge and still didn't seem quite as sharp.
I know I answered this question recently but cannot find where I did. I wonder how many of my posts disappear?

Anyway, both low hardness and high retained austenite make removing a burr more difficult. That's why it's sometimes a fallacy that low hardness knives are easy to sharpen.

Edit: Nevermind I found it. Maybe more people would read what I say if I didn't say things so succinctly, or at least if I made every sentence a new paragraph. http://www.kitchenknifeforums.com/showthread.php?2704-Which-stainless-can-attain-the-highest-level-of-sharpness&p=41151&highlight=cowry#post41151

Lefty
09-10-2011, 09:54 AM
Larrin, I got told to put more paragraphs in my posts a long time ago.
I
Listened.
It seems
To work.
:D