Your ideal rockwell hardness?

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DangerZone98

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Dec 7, 2019
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Relative to the big three of steel, heat treat, and geometry, how important is rockwell hardness? What would be your ideal hardness values for different knife roles? (chopper, kitchen work, edc, hunter, etc.)
 
I think the big three are hardness, toughness and corrosion resistance.
Depending on what your going to use the knife for.......
You my choose a trade off of one quality for another.
Usually the want is to find a balance of the qualities.
 
EDC folder, as high as it can go, Maxamet or Sandrin Torino, I don't care (above 70).
EDC fixed or outdoors fixed or choppers are the opposite, as tough as it can go, it will depend on the steel, I am happy with 58. But I remember my 1075 Condors at 50-55 were too soft for me, I need more edge holding than that.
 
Maybe I'm misunderstanding the question, but heat treatment is the process that generates the hardness... so your question is really asking how important is heat treatment. Very important, though you haven't really said what the purpose of the tool is.

ESEE runs their 1095 on the soft side in favor of toughness. (55-57 iirc)
ESEE runs their S35VN on the hard side in favor of edge retention. (60-61 iirc)

I would say that range expresses the HRC's that I'm familiar with, including axes.
I've never wanted anything softer, and never used anything harder.
 
There are really 3 material properties of concern that are interrelated with hardness: toughness, abrasion resistance (edge retention), and corrosion resistance. These material properties are a function of the steel chemistry and heat treatment. Each steel obtains it's maximum hardness after quenching, then the steel is tempered to reach a desired toughness (which reduces the hardness).

Choosing a target hardness really only makes sense once you have already chosen the blade geometry, type of steel, and target toughness. You can then choose your quenching and tempering processes to meet your your target toughness and hardness criteria.

To learn more, I suggest checking out knifesteelnerds.com.
 
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It's ll about the trade-offs between the various qualities of the blade.
S110v is pretty darn hard. You might not dull it: but you'll probably chip it.
You need to also keep in mind that re-sharpening a "hard" blade will be more work...
look for a measure of toughness...
 
In general I want my folding knives and smaller fixed blades that are under 4 inches to have better edge holding which generally means a higher hardness.

I want my bigger fixed blades 4 inch and over to have more toughness in relation to length which generally means not as high hardness as it could be.

All of my points are in general terms because it depends on the type of steel and several aspects such as blade thickness, type of grind, geometry, what I intend to do with it and the conditions it will be exposed to. There’s other considerations to make in personal preference and design. So there isn’t any one hardness that can be applied to all steels in general.
 
Danke42 said:
Mine goes up to 11
Click to expand...


330px-Spinal_Tap_-_Up_to_Eleven.jpg
 
Ideally (big stress on this word) we need a steel or equivalent material that is 10 on the mohs scale (so way above 70 HRC), 100+ ft/lb in toughhess on standard v-notch charpy test, and corrosion resistance on par with commercially pure titanium.

That steel or equivalent material would be ideal for any situations, be it chopper (thicker stock) or kitchen (thinner stock), and every type of knife in between.

In all seriousness, that's an odd way to frame the question because hardness is extremely important for having a knife to even hold an edge for any real use. I'm not sure where the cutoff point is, but I'd say that 55 would be the bare minimum a knife needs to be do have structural integrity for an edge (yea, I know, throwing knives are hardened much softer, but they're not used primarily for cutting stuff).


You can't use pot metal to make a knife. Well, you can, it just won't be a very good knife and will be difficult to sharpen and it won't hold an edge long enough to do real work.

With modern tech, the hardness/toughness debate is kinda moot. We have highly alloyed 60+ HRC-possible steels that have higher toughness than low alloyed 55-57 HRC steels. Some of the steel/geometry used in those BladeSports chopper knives could be easily adapted to kitchen duty.
 
Definitely do a deep dive with Knife Steel Nerds. Different steels do different things at different hardness. Hardness also isn't always indicative of quality, a good heat treatment, or ultimate performance.

For instance, a Ganzo in Chinese D2 might be 62 HRC. It might outperform Chinese D2 from Steel Will or other more reputable companies. However, it might not outperform D2 with a better heat treatment at 60 or 61 HRC. It also might also fall short of a Civivi in 9Cr18Mov at 60 HRC.
 
Spears said:
Ideally (big stress on this word) we need a steel or equivalent material that is 10 on the mohs scale (so way above 70 HRC), 100+ ft/lb in toughhess on standard v-notch charpy test, and corrosion resistance on par with commercially pure titanium.

That steel or equivalent material would be ideal for any situations, be it chopper (thicker stock) or kitchen (thinner stock), and every type of knife in between.

In all seriousness, that's an odd way to frame the question because hardness is extremely important for having a knife to even hold an edge for any real use. I'm not sure where the cutoff point is, but I'd say that 55 would be the bare minimum a knife needs to be do have structural integrity for an edge (yea, I know, throwing knives are hardened much softer, but they're not used primarily for cutting stuff).


You can't use pot metal to make a knife. Well, you can, it just won't be a very good knife and will be difficult to sharpen and it won't hold an edge long enough to do real work.

With modern tech, the hardness/toughness debate is kinda moot. We have highly alloyed 60+ HRC-possible steels that have higher toughness than low alloyed 55-57 HRC steels. Some of the steel/geometry used in those BladeSports chopper knives could be easily adapted to kitchen duty.
Click to expand...
Yeah, good thing Cedric and Ada exposed that. Lots of non-knife folk probably fell for that.

I’ll admit I’m not that familiar with the exact mechanics behind HRC. I know the Kershaw Camp series has HRC 56 I think? And the Beckers are around 58-60 (correct if I’m wrong). I’ve also heard that steels like ZDP-189 can comfortably reach into the range of 60s.
 
65+ for Kitchen knives and everything except hard use choppers, then I don't mind a little lower. I always keep a soft steel knife on me though in case my hard knives get damaged, I know I can use the soft steel knife and reprofile it on the go.
 
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