Which blade steel can be hardened the MOST?

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Folderguy

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Which blade steel can be hardened the MOST? As in achieve the highest HRC rating, and how high is that?

I'm interested in having a custom knife made with whatever steel that might be. I'm not worried about it being brittle, as it will only see duty as a slicer.

Also, it doesn't matter if the steel is stainless or not. I imagine the steel with the greatest potential will be a high carbon steel, but most of all, I want a steel that after I've put a razor's edge on it will stay that way for a LONG time...
 
I think you're confusing hardness and wear resistance ! Hardness is a measure of the strength of the matrix. Wear resistance is mostly a measure of the properties of the carbides.
Details of the exact application would help , material to cut ,type of edge etc.
 
Broad Question! If you are slicing meat. vegies and the sort. I do not see the need to have some sort of super steel. Other steel experts will chime in but for now you have me.

S30V on the low end and their are many on the higher end but in my opinion not necessary. On a proper board "IE end grain up board well treated" slicing the above mentioned I would for myself use CPM-S30V-PM CPM-154-cm, then you can go to the harder steels which I do not aquaint myself with because I feel I do not need them. I have had a spyderco Cat with CPM-S30V-PM and it seemed when I cut harder substances like those dangerously hard clamshell packs. I thought to myself I bet I have to strop now. Not the case. It almost seemed that the clamshell sharpened the S30V.

I would be only guessing but ZPD-189 or just 89 I forget and then their are the tool steels. A-1 tool steel. I am having a knife made for myself as I type. It has been a few months but you wait for something good. I chose S30V.

Well elmax comes to mind but I have no idea what that is. Now to make a good slicing knife it would have to be realtivly thin I suppose. I would not want to drop a knife, and it will happen, that is hardened to 64 rockwell or more. Just not feasable. In a thin blade ideal for slicing I would not want to go over 59 rockwell or therebouts. Drop a superhard thin blade that is ideal for slicing and it is back to the shop for repairs. My opinion only. S30V
 
mete said:
I think you're confusing hardness and wear resistance ! Hardness is a measure of the strength of the matrix. Wear resistance is mostly a measure of the properties of the carbides.
Details of the exact application would help , material to cut ,type of edge etc.
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There is no exact application. What'll I be cutting? Everything from steak, to veggies on a cutting board, to bread, to cheese, to cardboard, paper. Won't be cutting steel. Also will be cutting plastic, as in those clamshell packs that everything seems to come in these days. FWIW, the steel used in those box cutter blades isn't too bad, but I'd like something even better.
 
nativecajun57 said:
Broad Question! If you are slicing meat. vegies and the sort. I do not see the need to have some sort of super steel. Other steel experts will chime in but for now you have me.

S30V on the low end and their are many on the higher end but in my opinion not necessary. On a proper board "IE end grain up board well treated" slicing the above mentioned I would for myself use CPM-S30V-PM CPM-154-cm, then you can go to the harder steels which I do not aquaint myself with because I feel I do not need them. I have had a spyderco Cat with CPM-S30V-PM and it seemed when I cut harder substances like those dangerously hard clamshell packs. I thought to myself I bet I have to strop now. Not the case. It almost seemed that the clamshell sharpened the S30V.

I would be only guessing but ZPD-189 or just 89 I forget and then their are the tool steels. A-1 tool steel. I am having a knife made for myself as I type. It has been a few months but you wait for something good. I chose S30V.

Well elmax comes to mind but I have no idea what that is. Now to make a good slicing knife it would have to be realtivly thin I suppose. I would not want to drop a knife, and it will happen, that is hardened to 64 rockwell or more. Just not feasable. In a thin blade ideal for slicing I would not want to go over 59 rockwell or therebouts. Drop a superhard thin blade that is ideal for slicing and it is back to the shop for repairs. My opinion only. S30V
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Yes, it is a broad question!

S30V is alright, but I have several knives in it, and to put it plainly, it's not good enough. Dulls too easily. Need to resharpen too often. I'd like to get it hair popping sharp and keep it that way, even after cutting through cardboard, plastic clamshell packs, cutting through cooked steak on a dinner plate, and so on.
 
How about Duratech CV? Pain in the but to work in, but SOG was able to make the Team Leader out of it.
 
Yeah - it also matters what sort of edge you want to keep on it. Something like CPM-10V is generally thought to be near the top of the heap in terms of wear resistance, and it is also capable of getting very hard (very, hard) but it does not want to hold as fine, and polished an edge as something like 52100, or Hitachi Super Blue.

The ability to hold a really fine, polished, edge (edge stability) -- and the ability to be hardened above 64HRC might be a better comprise...
 
If you want as hard as you can get and are not worried about brittle, you may want to consider a ceramic blade. Harder than any steel, definitely brittle, and difficult to sharpen IMO, but can be made very sharp with practice, patience, and fine grit diamond sharpening films or pastes. And Harbor Freight has some super cheap ones to experiment with so you don't have to risk ruining an expensive model early on.
 
guyfalks said:
If you want as hard as you can get and are not worried about brittle, you may want to consider a ceramic blade. Harder than any steel, definitely brittle, and difficult to sharpen IMO, but can be made very sharp with practice, patience, and fine grit diamond sharpening films or pastes. And Harbor Freight has some super cheap ones to experiment with so you don't have to risk ruining an expensive model early on.
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Great suggestion, thanks!
 
Just food for thought: I recently made a large chef's knife for a Baltimore restaurant owner. She could have had any steel, but she let me pick. She just wanted something crazy sharp with great edge retention. I chose to use 1095FG from Aldo Bruno's custom, fine grained, melt; it's low impurity 1095 with enough vanadium thrown in to pin the grain boundaries during heat treatment. I had the blade hardened to 64 HRC at a 320 degree temper to coincide with the torsional toughness peak of that steel. You would not believe that the knife was 1095 if your experience with that steel was limited to (very respectable) mass produced knives 6-8HRC points lower. At that hardness 1095 is still about as tough as 154cm or VG10 are at their customary hardnesses.

If you are open to trying something other than one of the CPM stainlesses, or high carbide tool steels, a low alloy or carbon steel with a clever heat treatment could also be an option.
 
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Great suggestion on the ceramic, the only precaution is hitting staples and other hard objects with it. Obviously I am no PhD in metallurgy, but I have learned enough to know that there is no such thing as a single be all end all steel. As some have suggested when it comes to steel there is always give and take. If you opt for maximum corrosion resistance you will lose something. If you opt for maximum hardness/wear resistance you will lose some else. In other words, a steel needs to be balanced to be a used in a specific format (folder vs fixed blade). Some people love carbon steel to death (me included), it's tough, easy to sharpen, and holds an edge for a long time (ESEE knives is a prime example of how 1095 can be done). Some favor a more stainless steel like S30V. Spyderco does an excelent job of heat treating S30V, it's very well balanced in toughness, edge retention, corrosion resistance, and wear resistance (at least in my area of use).
 
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hkpokes_you said:
Just food for thought: I recently made a large chef's knife for a Baltimore restaurant owner. She could have had any steel, but she let me pick. She just wanted something crazy sharp with great edge retention. I chose to use 1095FG from Aldo Bruno's custom, fine grained, melt; it's low impurity 1095 with enough vanadium thrown in to pin the grain boundaries during heat treatment. I had the blade hardened to 64 HRC at a 320 degree temper to coincide with the torsional toughness peak of that steel. You would not believe that the knife was 1095 if your experience with that steel was limited to (very respectable) mass produced knives 6-8HRC points lower. At that hardness 1095 is still about as tough as 154cm or VG10 are at their customary hardnesses.

If you are open to trying something other than one of the CPM stainlesses, or high carbide tool steels, a low alloy or carbon steel with a clever heat treatment could also be an option.
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I like the way you think sir... most appreciated! Excellent post!
 
I think that we may be over thinking this The O.P. asked for the steel with the highest hardness, he wants an extreme, which to my knowledge is probably CPM Rex121 it can go as high as 71 HRc. Also while it is true that hardness doesn't necessarily equivilate to wear resistance the steels that can be hardened in the ranges we are talking about are also going to be designed for wear applications . Additionally a harder matrix will wear less, and probably hold the carbides better.

That being said ceramics, carbide, or tantung may be an option, but those are really brittle, and super hard to get razor sharp, besides that you are going to have a tough time finding a maker who will do these, and its gonna be expensive
 
Nebulae said:
I think that we may be over thinking this The O.P. asked for the steel with the highest hardness, he wants an extreme, which to my knowledge is probably CPM Rex121 it can go as high as 71 HRc. Also while it is true that hardness doesn't necessarily equivilate to wear resistance the steels that can be hardened in the ranges we are talking about are also going to be designed for wear applications . Additionally a harder matrix will wear less, and probably hold the carbides better.

That being said ceramics, carbide, or tantung may be an option, but those are really brittle, and super hard to get razor sharp, besides that you are going to have a tough time finding a maker who will do these, and its gonna be expensive
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That's exactly the idea (in the bolded text). I'm not looking for something that is really expensive, but reasonably priced.

Razor sharp, very resistant to losing the edge, brittle is ok but not to the point where if I drop the knife on the kitchen floor it's going to shatter.
 
If you don't want it to be brittle, to the point of shattering, if dropped, maybe you need one of the "non-steels". These would include, Vasco Wear, Talonite, or Stellite 6K. Once sharpened, they will keep an edge for an incredible length of time. You will need a very good sharpener when they finally do get dull, which would be a loooong time, cutting meat, and veggies. Of course, the next thing is to find a maker who will even work with this kind of material. They are very hard on machining, and grinding tools. I only know of one, that made one for me, a long time ago.

EarlFH
 
Folderguy said:
Which blade steel can be hardened the MOST? As in achieve the highest HRC rating, and how high is that?
....but most of all, I want a steel that after I've put a razor's edge on it will stay that way for a LONG time...S30V is alright, but I have several knives in it, and to put it plainly, it's not good enough. Dulls too easily. Need to resharpen too often.
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ZDP-189 has great edge retention and is probably the hardest you will find in custom or production knives (around 64 RC) and IMHO, has better edge retention.

I think the real issue with knives that are fit for kitchen duty is shape, width, and length. The general rule I follow is that the knife should be 2-3x longer than the food you are cutting through. Nothing more difficult than splitting a chicken down the breast with a 3.5" pocket knife when a 8-12" chef knife will do the job much easier. Conversely, breaking down or opening boxes is better handled by smaller blades.
 
Perhaps one of the Boker CeraTitan series would be a good option as well.
 
ubuwalker31 said:
ZDP-189 has great edge retention and is probably the hardest you will find in custom or production knives (around 64 RC) and IMHO, has better edge retention.

I think the real issue with knives that are fit for kitchen duty is shape, width, and length. The general rule I follow is that the knife should be 2-3x longer than the food you are cutting through. Nothing more difficult than splitting a chicken down the breast with a 3.5" pocket knife when a 8-12" chef knife will do the job much easier. Conversely, breaking down or opening boxes is better handled by smaller blades.
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I've heard great things about ZDP-189 and M4, too. Between these two steels, which would you recommend? Also, how critical is the heat treatment of each steel to get the desired hardness and temper?
 
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