1095 steel?

I’m sure there is a bunch of cheap 1095 out there that delivers subpar performance. The same could be said for pretty much any steel, super or not. The only knives I have that are 1095 and see real use is my Beckers. All I know is that they work for me, and I could trust my life to them. I’m a “if it ain’t broke, don’t fix it” kinda guy.
 
66 Rc is pretty much maximum as quenched hardness for 1095. I don't know anyone running 1095 at 65 or 66 Rc. That's almost no tempering and I don't think it would perform very well no matter what.
 
DeadboxHero said:
The Rockwell hardness is not going to tell you the full picture of what's going on in the microstructure of the steel which is actually the main factor for why something is performing better or worse at the same hardness.

Some of the ways some people are going to heat treat to 65-66rc with 1095 is certainly going to be a brittle pile of junk. That doesn't mean that the hardness is too high it just means that it's difficult to achieve that hardness with a good microstructure without some extra steps , knowledge and best practices with processing.
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Yup, as I also said in a previous post:

"High carbon steels (1095 in particular) are very dependent upon quality tempering/heat treatment in order to produce a blade that has decent edge retention. Not that heat treatment is not important in ANY steel, but my experiences have shown that 1095 is very temperamental with regards to heat treating. There does not appear to be a lot of middle-ground or margin of error in 1095. It is either good, or it is not."
 
Here's a link to some info from Kevin Cashen's website where he says the as quenched Hardness of 1095 is approximately 66 Rc. I have VERY good reasons to believe his data.

cashenblades.com

1095

1095 is a very simple high carbon steel that is easy to shape by forging; it lacks some of the manganese of the other 10XX series and thus has a slightly lower hardenability. It added carbon creates a carbon rich martensite with plenty of free carbide for good abrasion resistance. The downside...
cashenblades.com cashenblades.com
 
DeadboxHero said:
The Rockwell hardness is not going to tell you the full picture of what's going on in the microstructure of the steel which is actually the main factor for why something is performing better or worse at the same hardness.

Some of the ways some people are going to heat treat to 65-66rc with 1095 is certainly going to be a brittle pile of junk. That doesn't mean that the hardness is too high it just means that it's difficult to achieve that hardness with a good microstructure without some extra steps , knowledge and best practices with processing.
Click to expand...
That's a good point, and you're right.

Almost 20 years ago, I got to demo a knife in 1095 at 65 or 66. Whoever heat treated this knew his stuff, not brittle at all and was amazing in edge retention. I didn't, but the owner claimed he could hammer it through nails and I don't doubt it. I had to give it back, but managed to obtain some M2 HSS from a guy in Canada trying to sell a bunch of power hacksaw blades. I have 2 knives in this steel, and they are extremely impressive.

Perhaps when I keep seeing the quotes "proper heat treatment", we should ask for more clarification. I love the higher hardness if it isn't made brittle. That probably takes some doing, I'm not a metallurgist. But I do know when it's done right, 1095 can hang with the big dogs.

I still hate chasing floppy burrs, lol.
 
When I was chasing ht protocols that produce max hardness - for 1095 (steel src: aldo, aks) consistently yielded 68-68.5rc AQ and a few times 69rrc AQ. it did involved BCMW HT with grain refinement + super quench + cryo.
DeadboxHero said:
No, it gets higher AQ, its dependant on your thermal cycling and austenitizing along with cryogenics
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1095 toughness: I found KnifeSteelNerds's toughness chart for carbon steels useful for conventional HT protocol but 1095 & O1 are need further study. O1 @ 58.5rc got 10 ft/lbs and 15ft/lbs, that is a 50% differences - hence more samples/data are needed... Of course, experiments aren't cheap, thereby thanks.

knifesteelnerds.com

Knife Steels Rated by a Metallurgist - Toughness, Edge Retention, and Corrosion Resistance - Knife Steel Nerds

Steel Metallurgist Larrin Thomas uses tests of knife steels to rate the steels and explains the factors that control performance.
knifesteelnerds.com knifesteelnerds.com

low-alloy-toughness-2-14-20.jpg


My conjecture (maybe based on common-sense or naive) - with metallurgically sound/consistent ht 1095 should has similar toughness as 52100. I got a request to make this knife in 8670 or 80CrV2 62-63rc edge differential to spine hardness.

Project8 V3 cropped.jpg

Well, I chose to build with 1095 with expectation to has toughness similar or better than 52100, and edge retention better than 8670 & 80CrV2 at same hardness. Though, I will aim for 63-65rc hardness but will lower it need higher impact load. I also will make a longer 1095 chopper to test my yet-new protocol as well.

1095/Carbon Edge Retention:
Edge retention drastically higher when matrix is close/at/harder than Silicate (~64rc) -additive of wear resistance - while steel must still has full elasticity range. High end kitchen knives users have known this for a long time.
 
Nothing wrong with 1095, it will be used in Case Carbon blades soon.
caseknives.com

The Case Edge – Past, Present & Future

Throughout more than one hundred years of history, the Case name has become synonymous with reliable blades which are individually honed by the hands of skilled artisans. During that time, Case has principally used two types of steel to make our blades. These include our original Chrome Vanadium...
caseknives.com caseknives.com
 
THAT is very good news to me. I've been using 1095 blades in my kitchen since the '70s and it works awfully well IMO. It takes a scary edge easily and if you wear it down you can get that edge back in 2 minutes.
 
drail said:
THAT is very good news to me. I've been using 1095 blades in my kitchen since the '70s and it works awfully well IMO. It takes a scary edge easily and if you wear it down you can get that edge back in 2 minutes.
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That's an understatement
 
Hashishiin said:
Can I ask what you would pick today, then? Knowing what you know, if you were going to go back to those wet conditions where the 1095 was dulling... what would you bring if you had full choice, money no object?
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Maybe s35vn it's pretty tough decently easy to sharpen, and not super expensive , I have several knives now in M390 it's great all around, unless you have to sharpen it in the field, but it can be done with a diamond card.. which I carry in my wallet. I just recently bought a spyderco in LN200 haven't done much in the field with it but the specs 'SOUND " good. if I were staying in the desert where I live, then 1095 would be a decent choice just not my first one, Bucks 420HC is another steel we use on the ranch, I buy a 112 for every ranch hand we hire,,
 
Hrafna173 said:
Maybe s35vn it's pretty tough decently easy to sharpen, and not super expensive , I have several knives now in M390 it's great all around, unless you have to sharpen it in the field, but it can be done with a diamond card.. which I carry in my wallet. I just recently bought a spyderco in LN200 haven't done much in the field with it but the specs 'SOUND " good. if I were staying in the desert where I live, then 1095 would be a decent choice just not my first one, Bucks 420HC is another steel we use on the ranch, I buy a 112 for every ranch hand we hire,,
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Interesting, thank you for your input! I have a large 7.5" knife in S35VN, my only one in the offering, and I was hoping it would have those qualities and could be used for heavier chores. I just received my first 110 two days ago, and am excited to put it to use. I have one of those diamond cards, too, now just to learn to use it!
 
J. Doyle said:
I'd like to see data on that. Got a link?
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The links you shared have no data on cold treatment, also thermal cycling was not required to show that the maximum as quenched hardness is above what you said its not able to go past. So no video is required to explain.

The reason for lower as quenched hardness you are experiencing is due to retained austenite which can be avoided by using a different austenitizing temperature and cold treatment. Thermal cycling will also change what hardness is achieved by even the same austinitizing temperature.


This was Admiral Steel 1095, Austenitized from as received condition.

1475°F 10min Parks 50, No Cryogenic Treatment.
65 HRC (average from 3 tests)

vGNSWPw.jpeg




1475°10min Parks 50, Cryogenic Treatment immediately after quenching (Liquid Nitrogen, immersion in liquid -320°F)

68 HRC (average from 3 tests)

TeoPe9M.jpeg


Hardness doesn't tell us everything about the mechanical properties of the steel, 65rc due to high retained austenite and untempered martensite is not the same as low retained austenite with tempered martensite at the same hardness (65rc) tempered down from 68rc.

The constituents of the microstructure are what is important.

Thin geometry requires high strength to support it. As Roman Landes says "Geometry Cuts"
 
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DeadboxHero said:
The links you shared have no data on cold treatment, also thermal cycling was not required to show that the maximum as quenched hardness is above what you said its not able to go past. So no video is required to explain.

The reason for lower as quenched hardness you are experiencing is due to retained austenite which can be avoided by using a different austenitizing temperature and cold treatment. Thermal cycling will also change what hardness is achieved by even the same austinitizing temperature.


This was Admiral Steel 1095, Austenitized from as received condition.

1475°F 10min Parks 50, No Cryogenic Treatment.
65 HRC (average from 3 tests)

vGNSWPw.jpeg




1475°10min Parks 50, Cryogenic Treatment immediately after quenching (Liquid Nitrogen, immersion in liquid -320°F)

68 HRC (average from 3 tests)

TeoPe9M.jpeg


Hardness doesn't tell us everything about the mechanical properties of the steel, 65rc due to high retained austenite and untempered martensite is not the same as low retained austenite with tempered martensite at the same hardness (65rc) tempered down from 68rc.

The constituents of the microstructure are what is important.

Thin geometry requires high strength to support it. As Roman Landes says "Geometry Cuts"
Click to expand...
Neat. But a couple things to point out....

1. I did not say it was "unable to go past" 66. I said 66 was "pretty much" the limit. Maybe small distinction but it's a difference nonetheless. Most people and companies are not getting higher as quenched hardness than 66. I have seen a few samples, including some of my own that reach 67.

2. I ALWAYS normalize and thermal cycle my steel.

3. I have excellent temp control and therefore don't have RA to any significant degree.

4. Personally I don't use cold treatments on simple steels because I don't see any measurable gain.

It's cool that you can eek out every last bit of hardness out of your steel. Your results are cool, but honestly lower than I was expecting from the way you were talking. I was thinking you might have found the secret to get it to 70 or maybe higher. ;) An rc point or two is great, but I wonder how much noticeable field difference an end user would see?
 
J. Doyle said:
Neat. But a couple things to point out....

1. I did not say it was "unable to go past" 66. I said 66 was "pretty much" the limit. Maybe small distinction but it's a difference nonetheless. Most people and companies are not getting higher as quenched hardness than 66. I have seen a few samples, including some of my own that reach 67.

2. I ALWAYS normalize and thermal cycle my steel.

3. I have excellent temp control and therefore don't have RA to any significant degree.

4. Personally I don't use cold treatments on simple steels because I don't see any measurable gain.

It's cool that you can eek out every last bit of hardness out of your steel. Your results are cool, but honestly lower than I was expecting from the way you were talking. I was thinking you might have found the secret to get it to 70 or maybe higher. ;) An rc point or two is great, but I wonder how much noticeable field difference an end user would see?
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1. I can only work with the information you posted not what your perceived intentions or thoughts are.

2. Normalizing is a part of thermal cycling. Refining grains and carbides doesn't change the fact that austenitizing temperature is the most significant factor for differences in hardness, toughness, strength, etc.

3. Control at a specific temperature doesn't change the fact that different Austenitizing temperatures are what is controlling retained austenite the most followed by cold treatment.

4. It's not about the small change in hardness as much as it's about removing undesirable features in the microstructure.

That wasn't any kind of secret heat treat that was just showing the difference Cryogenics makes.

If there's that much of a change in hardness than there is a significant amount of retained austenite that's being converted with the cold treatment.

S sodak seems to notice a difference

In my experience, the edge has better resistance to deformation and better edge taking and deburring.
 
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