PSF27/D2 Interest

[mb>]

Thought I'd toss out a poll just to gauge interest in D2 as a steel option. I know several have expressed interest, while others may not care. If there's enough interest, maybe we can get a spot on the white board for this nice alternative offering to the more standard (and great) D3V.

I know it has been offered in the past on the EDC and HDFK. Personally, I'd be thrilled to add a smaller blade to my Carothers quiver that is biased more towards abrasion resistance for skinning type work.

 

[WValtakis]

In on one

~Chip

 

[patrickguignot]

Personally, I'd be thrilled to add a smaller blade to my Carothers quiver that is biased more towards abrasion resistance for skinning type work.

Not interested at all.
D2 is a low toughness steel and if you want high abrasion resistance you have much better alternatives.

 

[WValtakis]

I wouldn't call Nathan's D2 "low toughness", lol. My boss went chop happy on semi-frozen Elk leg bones (4 animals worth) with the HDFK pictured above, those small glints in the edge were the only damage. Took 5 minutes on a DMT fine bench stone to get them out

He didn't even notice the edge damage, he thought I was going to be pissed about the patina, lol.

~Chip

 

[AndreLinoge]

PSF! PSF! PSF! PSF!

Woooooo!

 

[mb>]

Not interested at all.
D2 is a low toughness steel and if you want high abrasion resistance you have much better alternatives.

That's cool. Like I said, just gauging interest.

A couple of points though. 1) Not all D2 is created equal. 2) Nathan has worked with PSF27/D2 quite a bit and has recommended it for the application I have in mind. That's why I'm asking about it here.

 

[patrickguignot]

I wouldn't call Nathan's D2 "low toughness", lol.

I don't know about Nathan's D2 but according to the tests done by Larrin and published on Knife Steel Nerds the D2 steel scored very low :

 

[Casinostocks]

Some bulletin board material in here. What's Nathan to do? Concentrate on and prep for that new Mori delivery or to take a bit of time to state again as to why D2 is nowadays "misunderstood" as a passé steel. My money is on both

 

[Mo2]

I don't know about Nathan's D2 but according to the tests done by Larrin and published on Knife Steel Nerds the D2 steel scored very low :

You might want to read alot of this.
https://www.jayfisher.com/Heat_Treating_Cryogenic_Processing_of_Knife_Blade_Steels.htm

Search toughness or tough if you just want to find some highlights.
Also one for specifically d2 https://www.jayfisher.com/D2_Wear_Resistance_King.htm

And

https://www.bladeforums.com/threads/any-questionson-cryogenics.218762/#post-18720941

 

[Cap’n Smudge]

I’ve always loved D2.
Would love a D2 EDC!
FK2 is my second choice, but would probably buy any of the “smaller” Carothers blades in PSF 27/D2.

 

[bubbaskyjacker]

Nate has done D2, 4v and a ton of work on D3V, why introduce something else when D3v is about as good as it gets.

It’s like having Ferrari build an F250

 

[amflud]

I like D2, but I prefer regular D2 over the CPM and PSF versions. I like the toothy edge you get with the large carbides.

 

[Hard Knocks]

I like D2, but I prefer regular D2 over the CPM and PSF versions. I like the toothy edge you get with the large carbides.

^This is what I'd be down for.

 

[Gusbuster]

If you want it for skinning, I think the EDC2 has more belly than the EDC3. The EDC3 with the swedge is more stabby, and less slicey.

 

[patrickguignot]

You might want to read alot of this.

Well at this point it's a question of credibility. I know Jay's website since several years and I read a lot of materials on his website. It's interesting but I read these articles with a huge grain of salt.
His opinion are controversial in the community (to say the least).
Also he's not a metalurgist.
And he's here to sell something to you and (more importantly) to try to differentiate from the other knife makers.

On the other hand Larrin is a PhD metallurgist.
He's not trying to sell something. And he actually tested and compared these steels and he report the results of these real tests with numerical values.

According to these tests D2 is low in toughness compared to the other steels tested.

 

[Gusbuster]

The OP said he was looking for something biased more towards abrasion resistance for skinning type work, not toughness.

 

[mb>]

If you want it for skinning, I think the EDC2 has more belly than the EDC3. The EDC3 with the swedge is more stabby, and less slicey.

Good observation Gus. I haven't compared the 2 that closely, but I was thinking with EDC3 here now, maybe EDC2 was done (?).

 

[Nathan the Machinist]

People tend to incorrectly correlate "toughness" with durability. While it's true there are more durable materials than D2, and it's true that it doesn't exhibit a high degree of ductility in a fracture, anyone claiming it's a weak material hasn't really used it. There are a number of internet experts (and I guess I'm one of them) making claims about the behavior of different knife steels. Some may look at the joules of energy absorbed by a fracture impact and claim (technically correctly) that D2 is not a tough steel. Other people, who have actually used knives, can tell you that in practice it is more durable in real use than other materials with higher impact test numbers. While it's true that its failure mode is frequently a clean break, one almost never sees this kind of failure in use. And if you're talking about a D2 blade given a cutlery heat treat it's a little different animal than one taken to the secondary hardening hump where there is a growth in carbides.

A diamond is also not very tough, but they're not easily broken and you'll almost never wear one out.

D2 is one of the better knife steels and it will frequently run circles around many of the new PM super steels in real use. There are valid reasons one might choose a different material for their use, but concerns about durability (in a small or medium sized knife) wouldn't be one of them.

 

[Grenock]

People tend to incorrectly correlate "toughness" with durability. While it's true there are more durable materials than D2, and it's true that it doesn't exhibit a high degree of ductility in a fracture, anyone claiming it's a weak material hasn't really used it. There are a number if internet experts (and I guess I'm one of them) making claims about the behavior of different knife steels. Some may look at the joules of energy absorbed by a fracture impact and claim (technically correctly) that D2 is not a tough steel. Other people, who have actually used knives, can tell you that in practice it is more durable in real use than other materials with higher impact test numbers. While it's true that its failure mode is frequently a clean break, one almost never sees this kind of failure in use. And if you're talking about a D2 blade given a cutlery heat treat it's a little different animal than one taken to the secondary hardening hump where there is a growth in carbides.

A diamond is also not very tough, but you'll almost never wear one out.

D2 is one of the better knife steels and it will frequently run circles around many of the new PM super steels in real use. There are valid reasons one might choose a different material for their use, but concerns about durability (in a small or medium sized knife) wouldn't be one of them.

......but the graphs, and the numbers........

 

[Cap’n Smudge]

I think people often confuse or conflate toughness and wear resistance. They are very separate properties (and I don’t think there is a clear correlation between them). In a knife (small/medium) that I want to stay sharp a long time - then I am looking for high wear resistance.
If I’m looking at a pry bar - then I want toughness.
... or that’s my understanding.