Serious blade damage, advice?

[Hubert S.]

I agree that they work best on softer knives (I have an old henckel probably around 56 RHC that touches up great on the steel).
I use them fairly precisely, holding a consistent angle etc, not flashing them together like some think should be done.
I guess part of the question is about your business philosophy. Places like CPK will tell their customers to go ahead and use the knives hard, they will fix them for free if necessary.
I don't know how many would come in for repair, but it instills confidence even in the more careful user, and no doubt increases sales.

I used to use a honing steel frequently for my Zwilling and Sabatier knives, but don't use it on the knives I've made. I sometimes use a leather strop with compound on them and that works pretty well for me to extend time between sharpening.

There are obviously some limits what "hard use" should entail. Frozen foods, bones, knife sharpening gadgets and use as a pry-bar are out for kitchen knives for sure. I don't really know where steel rods fall in the spectrum or how useful they would be for a hard knife. This is just a hobby for me, so I have not really thought about a business philosophy. I would probably suggest a strop or ceramic hone instead of steel, though.

 

[Cushing H.]

a couple comments, as I earlier started a thread on a related topic - i.e. that a softer steel is "easier" to touch up. Sharpening steels are *claimed* to just straighten out a rolled edge .... but I cannot help but think from my experience that they also create some micro-serrations that make the edge bite better. **this is for softer steels only*. On harder blades they only chip the edge (just to see I actually tried it once - yes - they do just chip the edge). Ceramic rods work for harder steels, but there is a limit beyond which you (or at least I) have to go back to a true sharpening process.

I know that there are people who would sing the praises of blades made from some of the newer, tough and hard, steels, and take them to cut through nails, or spatchcocking a chicken .... but I dont know, that just makes me cringe and I can not bring myself to do so (and wont recommend it to anyone). I have one knife (an old Sabatier) that is a "boning" knife - 5 inch blade, thicker steel, higher thickness behind the edge, and sharpened with a higher edge angle (25 degrees). I use it to go through cartilage and to pry into joints, and, occasionally, to spatchcock. As soon as that chore is done, I put that boning knife aside, and pick up something more made for slicing - and dont go near the bones with it. Just FWIW....

 

[fitzo]

Indeed, 1200-2000 grit ceramic rods are hones and not meant for sharpening. There are coarser sticks that could do that, but why? Belt, stones, coarse rods, whatever at that point; eventually every frequently honed knife needs the edge thinned above it to provide its best continuing service.

 

[scott kozub]

I just had my first edge damage come back to me on a professionally used knife acoupke weeks ago. AEBL at 0.002 tbe. A small sixteenth of an inch chip. Said he was processing chickens. I like to run my AEBL at 64 Hrc. First thing I did when getting it back was started whailing on a piece of antler. It took some waves but no chipping. Also passed the brass rod test. I'm surprised a 0.010 AEBL would chip. Maybe it got dropped on a granite counter.

In regards to honing rods. I use them all the time on my own knives. I like the bite they leave. I hear all the time not to use steel on high hardness knives dye to chipping but ceramic is ok. Why would ceramic be any different? I'm hoping someone can shed some light.

 

[Hubert S.]

I just had my first edge damage come back to me on a professionally used knife acoupke weeks ago. AEBL at 0.002 tbe. A small sixteenth of an inch chip. Said he was processing chickens. I like to run my AEBL at 64 Hrc. First thing I did when getting it back was started whailing on a piece of antler. It took some waves but no chipping. Also passed the brass rod test. I'm surprised a 0.010 AEBL would chip. Maybe it got dropped on a granite counter.

In regards to honing rods. I use them all the time on my own knives. I like the bite they leave. I hear all the time not to use steel on high hardness knives dye to chipping but ceramic is ok. Why would ceramic be any different? I'm hoping someone can shed some light.

I do not really understand the brass rod test. I've read about it, watched videos and tried it. I can either flex, bend or chip my blades depending on how I push against the rod. It seems utterly subjective, just like hitting stuff. I recently whacked a thin blade into the rim of an aluminum can repeatedly for no particular reason and it did fine until it got stuck pretty hard and I twisted it a bit to free it and got a little chip. Not a scientific test, but I guess now I know not to use a kitchen knife to cut aluminum.

I would like to know about the honing steel vs ceramic or diamond rods as well. My understanding is that the latter work by abrading whereas the former works by straightening, and that harder steels are less amenable to straightening and more prone to chipping. As Horsewright says, quién sabe? It's good to hear from somebody who has tried the steel with good results, but then again, there is Cushing's experience. I wonder what the difference is.

I am curious about the 64 HRC. What temperature do you use for tempering?

 

[scott kozub]

I'll do an initial temper at 200 (after which the hardness rises) and then multiple creeping up till I hit the target hardness. I also soak in LN. I'll sometimes do several tempers checking the hardness at each stage. There's a really good thread here on AEB-l heat treating. I'm willing to risk a little chipping to get the maximum performance and I tell my customers that. If they are concerned I'll draw it back to 62. My first knives were at 60 and I wasn't overly impressed with them until I started treating a little higher.

I should note that I'm testing with an Ames hardness tester. I have a 42hrc test block that it tests perfectly on and I have tested knives of known hardness for repairs. I do occasionally get some high reading here and there.

https://www.bladeforums.com/threads/strange-cryo-on-aeb-l-anomaly.1646288/

 

[Hubert S.]

I'll do an initial temper at 200 (after which the hardness rises) and then multiple creeping up till I hit the target hardness. I also soak in LN. I'll sometimes do several tempers checking the hardness at each stage. There's a really good thread here on AEB-l heat treating. I'm willing to risk a little chipping to get the maximum performance and I tell my customers that. If they are concerned I'll draw it back to 62. My first knives were at 60 and I wasn't overly impressed with them until I started treating a little higher.

I should note that I'm testing with an Ames hardness tester. I have a 42hrc test block that it tests perfectly on and I have tested knives of known hardness for repairs. I do occasionally get some high reading here and there.

https://www.bladeforums.com/threads/strange-cryo-on-aeb-l-anomaly.1646288/

Thank you, Scott. I really need to get a hardness tester and approach it the same way you do, creep up to the desired hardness. I used to be able to use the hardness tester at the university here, but with the pandemic that's not really an option at the moment. It is a bit of an expensive toy for a hobbyist, but I've almost talked myself into it.

 

[Natlek]

AEB-L ..............60-61 HRC is good thing .AEB-L on 63 hrc is same as if you take 100 HP car and tune engine on 200Hp......don t except to last that engine long time !

 

[Hubert S.]

AEB-L ..............60-61 HRC is good thing .AEB-L on 63 hrc is same as if you take 100 HP car and tune engine on 200Hp......don t except to last that engine long time !

Have you had failures with AEB-L at 63? I have made a couple that measured at 62 and have had no chipping problems, and I have read many credible accounts from other makers that go harder, including from Scott above. The data on Larrin's page about AEB-L also indicates that AEB-L should be suitable for kitchen knives at high hardness.

 

[CallumRD1]

I have a couple dozen kitchen knives in circulation (friends and family mostly) made from AEB-L at HRC 62-63 and I've had none of them report any chipping (except for one where it was dropped on a tile floor and the last 3mm of the tip broke off). All were ground essentially to zero before sharpening and are exceedingly thin and sharp. I did advise them to not use the knives on anything frozen or on bones, but otherwise they get use for normal food prep by people less careful with their knives than I am.

Edit: I even had one gyuto get snagged by a scotch brite belt during finishing and it was thrown down onto a concrete slab very hard. The only damage was that about 4mm of the tip was knocked off and the heel distorted sideways just a touch. There was a little scuff on the blade where it bit halfway through the scotch brite belt but the edge was completely unaffected (at this point it was ground to zero and easily sharp enough to cut paper). It was very easy to fix and I'm still using that knife to this day.

 

[Londinium Armoury]

With the honing steels, it could be people are holding them at the wrong angle, and it's hitting the blade head on or skipping and bumping up against the apex, and people have experienced chipping due to incorrect usage?
I can't see why a honing steel would be bad but a ceramic hone wouldn't, can't be due to hardness because ceramic hones are way harder than steels.
Maybe some of the fluted types have caught onto a hard apex and damaged it, no idea, seems like user error to me instead of incompatible tool.

 

[FredyCro]

With the honing steels, it could be people are holding them at the wrong angle, and it's hitting the blade head on or skipping and bumping up against the apex, and people have experienced chipping due to incorrect usage?
I can't see why a honing steel would be bad but a ceramic hone wouldn't, can't be due to hardness because ceramic hones are way harder than steels.
Maybe some of the fluted types have caught onto a hard apex and damaged it, no idea, seems like user error to me instead of incompatible tool.

Maybe the cheap steel honing rods with ridges are catching the edge and ripping out pieces. I never liked honing rods. Since I discovered diamond stones I also don't use water stones. Leather for stroping and refreshing the edge. Diamond stone for the rest. Especially if stainless.

 

[Londinium Armoury]

Maybe the cheap steel honing rods with ridges are catching the edge and ripping out pieces. I never liked honing rods. Since I discovered diamond stones I also don't use water stones. Leather for stroping and refreshing the edge. Diamond stone for the rest. Especially if stainless.

That's what I was thinking, I've never used those fluted ridge honing steels, but i've seen plenty of them around and on online stores. People see chefs using them in a very speedy fashion as well, so maybe it chips blades when people try to do it very fast and accidentally bash the blade at an awkward angle right on the apex.
I still use water stones, as well as ceramic rods I only really use diamond plates / stones when reprofiling steels with a lot of vanadium in the alloy. I still sharpen and touch up edges using old King stones, even things like S35VN. I have mostly switched over to exclusively using ceramic rods for sharpening and honing, I rarely even use my stones anymore unless i'm repairing chips.

 

[scott kozub]

That's what I was thinking, I've never used those fluted ridge honing steels, but i've seen plenty of them around and on online stores. People see chefs using them in a very speedy fashion as well, so maybe it chips blades when people try to do it very fast and accidentally bash the blade at an awkward angle right on the apex.
I still use water stones, as well as ceramic rods I only really use diamond plates / stones when reprofiling steels with a lot of vanadium in the alloy. I still sharpen and touch up edges using old King stones, even things like S35VN. I have mostly switched over to exclusively using ceramic rods for sharpening and honing, I rarely even use my stones anymore unless i'm repairing chips.

Agreed I like a honing steel. I place the knife against it softly and draw it along slowly and methodically. With pressure you can feel any spots where blade almost catches where the edge is out of alignment. A few swipes and the bite is back. I see doing it fast and that makes me cringe. I never go fast. No way to control the angle that way.

 

[Londinium Armoury]

Agreed I like a honing steel. I place the knife against it softly and draw it along slowly and methodically. With pressure you can feel any spots where blade almost catches where the edge is out of alignment. A few swipes and the bite is back. I see doing it fast and that makes me cringe. I never go fast. No way to control the angle that way.

I'm the same even with ceramic rods, water stones and systems like the sharp maker. I always go slow, I think lots of people sharpen too fast, I go slow and steady to make sure I don't keep changing angle. Going fast just improves your chances to slightly changing angle and messing up the apex, going slower probably gives faster consistant results.

 

[daizee]

You can get most of the benefit of cold-quenching with dry ice if LN is not practical.

I went and made a high-hardness, very smooth, honing steel out of a scrap of 1084. That's what my blades see occasionally. I'm a fan of AEB-L at 61-62, but I wouldn't go past 62 on purpose. Maybe I'm just chicken.