How brittle is D2?

So long time knifemakers Jimmy Lile, Chubby Hueske, Ted Dowell, Mike Leach who all use D2 as their PRIMARY steel for all their knife models made an inferior choice? Not a factor but 3 of the makers mentioned above were founding Guild members.
All 4 knifemakers mentioned(2 deceased) have been making knives for 30-50 years, full time for all kinds of customers. If there was anything inferior about D2, they would have known about it a long time ago.
I know Ted has experimented with a bunch of steels over many years including M2, F2 and the T series steels. Yet he keeps using D2, even for his camp knives, and have not received any complaints about them.
 
I just showed my old neighbor (who stopped by to pick up his mail) that just moved the post by CS . You know the one about how D2 just doesn't cut to his standards and he just rolled his eyes and said, 'tell that to bambie' :D LOL. Keep in mind he has not read any of the other posts and I didn't mention a thing about the other stuff we said about number of deer or anything else. Anyway, I got a laugh out of it too.

STR
 
How come you never tried to hammer that Safari Skinner through a car hinge?

That was actually Thom's bright idea to suggest that to my brother on Busse's forum so it was done with a Howling Rat (which also had the same edge angle from Busse as Dozier' uses). The Rat eventually broke because of poor technique while it was being struck with a 28 on framing hammer. I had also made the edge much more acute than than stock configuration. It was at about 10 degrees per side and I had thinned the primary grind. Even then though it would have cut the door off with no problems had he cut through the bottom hinge first, the Dozier Agent broke immediately, but of course D2 is far more brittle than 52100. If you want to cut a door of a car with the Safari Skinner then go ahead, I offered to send it to you earlier this year. It would be expected to be lower than the Howling Rat but much higher than the Agent. It also had no trouble matching the edge retention of the Agent slicing abrasive material.

M2 is one of those up there with O1 for rusting ...

The corrosion resistance is significantly higher than O1, but lower than D2 which has more chromium dissolved, how much depends on how it is austenized, but 6-8% tends to be normal. Johnston noted that 1095 had a problem for meat cutters as the edge retention was lower than expected compared to stainless which was attributed to corrosion, M2 did not have such issues and far outperformed ATS34.

I know 1095 takes a great edge, but darned if I know if D2 does.

At the angles they use you will not see a difference in initial sharpness.

All I want is just want a good sharp knife that is reasonably easy to sharpen.

1095 would be much better for you.

Actually, all my Doziers have pretty obtuse edges.

It would probably be good to note the reference here because obtuse means different things, Dozier is much more acute than TOP's but more obtuse than the thinner Spyderco models like the Calypso Jr. for example.

The reason I say this, is because a year or so ago, I was experimenting with a bunch of D2 knives, and found they chipped and indented very easily once the edge bevel was thinned out too much.

Take a piece of wire which is similar in thickness to the carbides in D2 and imagine testing its strength, what do you think happens? The strength will just be the carbide/matrix bond which is very low compared to the internal matrix cohesion. This is why high carbide steels do so poorly when the edge is loaded. Landes measured this directly, it isn't a theory that D2 has poor edge strength at low angles.

M2 does much better than D2 because the carbide volume is much lower and the carbides are MUCH smaller it is also 5-6 points hard. They are not in the same class edge stability wise. D2 is a low class three, pretty much the worst cutlery steel, and M2 is a high class II or low class I.

[D2]

Put a rough edge on it (meaning rough in terms of grit size, not quality), and you have a D2 knife that keeps an edge for a very long time cutting through rough hide and dirty rope.

Yes, now use D7 or A11 if you really want to see long term slicing aggression. Compare a 0.005"/10 degree Wilson in 10V at 64/65 HRC to a Dozier in D2 at 60/61 HRC at 0.015"/15 degrees. Actually if you want to see something interesting, compare a 0.005"/10 degree 420J2 blade slicing hemp rope versus that Dozier. Use Goddards scale testing method and see which one performs better. Or just go back on rec.knives and read what Mike Swaim did ten years ago.

I'm testing D2 against CPM D2 right now, and they're both tougher than me!

Yes, that is their strength, slicing with a coarse finish, now sharpen them to a really high polish, reduce the edge angle under 10 degrees and see how long they hold a high sharpness push cutting.

I'd like to use one of Alvin's knives. It would help if one knew how to reach this person to set that up though.

Go on rec.knives and ask him. This is one of his first knives :

HSSknife.jpg


The edge angle is 5 degrees, still think a 15+ Dozier is not obtuse? It is 200%+ greater in edge angle, in comparison the heaviest ground Busse I have seen is only 15% greater in angle than the most acute Dozier. Now if you want to start calling Busse edges obtuse compared to Dozier then obtuse is not even strong enough to compare Dozier to Johnston.

But Alvin makes his knife to cut which is why they are so thin and acute, they are not meant to pry or chop, and no impact splitting. Ok those ones anyway, he is currently making some blades in L6 which are intended for that kind of utility work where a much tougher and stronger steel is needed. But that does not mean the 1095/O1/M2 blades are just paper cutters, you can cut wire, metal flashing, sods, read the reviews to note what they can do and what it takes to break them, I took a small piece out of the primary grind on the 63 HRC O1 blade rocking it through a hard spruce limb.

-Cliff
 
It would probably be good to note the reference here because obtuse means different things, Dozier is much more acute than TOP's but more obtuse than the thinner Spyderco models like the Calypso Jr. for example.

Yes, now use D7 or A11 if you really want to see long term slicing aggression. Compare a 0.005"/10 degree Wilson in 10V at 64/65 HRC to a Dozier in D2 at 60/61 HRC at 0.015"/15 degrees. Actually if you want to see something interesting, compare a 0.005"/10 degree 420J2 blade slicing hemp rope versus that Dozier. Use Goddards scale testing method and see which one performs better. Or just go back on rec.knives and read what Mike Swaim did ten years ago.
-Cliff

Good points. I'll measure the angle on my edgepro, I seem to recall around 20 per side, but could be wrong there.

Wilson in 10V at 64/65? I think I can dig one of those up, but I don't know how long my elbow can hold out.... :D I might have to read rec.knives, it's easier than duplicating those tests. I'm finding out how difficult rope cutting can be...
 
I'll measure the angle on my edgepro, I seem to recall around 20 per side, but could be wrong there.

Yes, that would be high enough for most steels to start to be stable, but for reference, the edge on my full size felling axe that I use on hardwoods is more acute.

Wilson in 10V at 64/65? I think I can dig one of those up ...

Mine is only a soft 62.5 HRC, got one of the early test pieces.

I'm finding out how difficult rope cutting can be...

Grind the D2 blade back to the primary, leave the edge as ground (4/5 degrees per side) with a 100 grit AO belt and see how long it will take before you reach Goddards stopping point of 30 lbs. He only got a few hundred with FFD2, with Sorg's regular D2 blade it took 2046 cuts on 3/8" hemp just to reach 20 lbs, good luck on ever reaching 30 lbs. I think that is actually an underestimate as the last thousand cuts I was sloppy. I always wanted to repeat that to get a better performance estimate, but the desire is not that strong to do another 2000 cuts, plus I think I need 4000 to really reach 20 lbs with proper technique.

-Cliff
 
I am SERIOUSLY getting tired of people saying that D-2 take a crappy edge and holds it forever! I say its a bunch of CRAP that person "A" said and everyone just repeats!!

:mad:

Do you consider a crappy edge one that can "POP" free standing arm hair?? I understand that it has a "coarser" grain structure than many of the above mentioned steels, but that is actually part of why I like it. It has a micro serration!

If you can't get a good edge on D-2 maybe it is your sharpening style or stones. A large extra fine diamond hone and a fine ceramic rod are all that are needed to get a hair popping "micro serrated" edge.

Cliff, I understand what you are saying about thin edges. I know you know I can grind them as thin as you or anyone else could want! I have also carry a Spyderco ZDP-189 Jess Horn EVERY single day for several months that has been reground to .007 prior to sharpening. I know what a very thin blade is capable of.

With that said a thin edge like that is not something I want to put on every knife I make. I can grind them super thin on request, but don't regularly because I don't want the head aches that would come with people chipping them out and breaking the tips off(it WOULD happen). I feel an edge in the .015-.020 range is nice and thin and easily sharpened and much stronger. It is also a big performance jump in geometry than most production knives out there.

Just my opinions....

Tom, a staunch D-2 supporter!:cool:
 
I am SERIOUSLY getting tired of people saying that D-2 take a crappy edge and holds it forever! I say its a bunch of CRAP that person "A" said and everyone just repeats!!

:mad:

Do you consider a crappy edge one that can "POP" free standing arm hair?? I understand that it has a "coarser" grain structure than many of the above mentioned steels, but that is actually part of why I like it. It has a micro serration!

If you can't get a good edge on D-2 maybe it is your sharpening style or stones. A large extra fine diamond hone and a fine ceramic rod are all that are needed to get a hair popping "micro serrated" edge.

Cliff, I understand what you are saying about thin edges. I know you know I can grind them as thin as you or anyone else could want! I have also carry a Spyderco ZDP-189 Jess Horn EVERY single day for several months that has been reground to .007 prior to sharpening. I know what a very thin blade is capable of.

With that said a thin edge like that is not something I want to put on every knife I make. I can grind them super thin on request, but don't regularly because I don't want the head aches that would come with people chipping them out and breaking the tips off(it WOULD happen). I feel an edge in the .015-.020 range is nice and thin and easily sharpened and much stronger. It is also a big performance jump in geometry than most production knives out there.

Just my opinions....

Tom, a staunch D-2 supporter!:cool:


I agree that it can get hair popping sharp Tom but in the hands of most end line users they rarely stay there at that level. Its only with guys like you and me that this is the case. D2 is one of my all time favorite steels. And I agree with your take on the thinner knives. Much as love my ZDP taken thin and the 12C27 edge I took down to .005 and the 13C26 I took down further but yet I carry the knife in my signiture line or the Marbles 1095 slip joint more than anything else as my go to knives.

Hunting jobs were always done with D2 something or other blades.

I can't see loaning out a knife like one of the thinner ones above to someone like my neighbor for even a few minutes time. That could be a bad deal for the condition of the knife real quick IMO.

STR
 
When people say a knife steel "TAKES" a crappy edge it means to me that it doesn't ever GET a "nice" edge.


I agree that it can get hair popping sharp Tom but in the hands of most end line users they rarely stay there at that level.

STR



Then I submit that it is not only D-2 that ends up with a crappy edge, but ALL steels! IF you don't sharpen or maintain your edge they will ALL end up with a CRAPPY edge. I don't think that is what people are talking about though!
 
whatever Tom says is gospel....as far as I'm concerned. :thumbup:


:D :D :D :D





Seriously guys....let's separate the facts from the myths!
 
Exactly. I think all steels end up with the same edge eventually but that D2 with the course edge like we see with the micro serrations as you called them just keeps cutting for longer. I think thats what people refer to when they say it keeps a good edge and really when they say it takes a crappy edge and keeps it for a long time I think its obviously misquoted because anyone thats used it and has grown to love it knows it can be damn sharp.

First time I saw it misquoted was here I think at Bob Engnath's statements about D2. http://users.ameritech.net/knives/steels.htm

STR
 
Tom iirc you made crossadas in d2 for keating? i would think a large fighter like that designed to parry against other weapons would be extremely hard on the knife.

i am curious as to why d2 was chosen for a crossada which is more of a short sword than a knife?
 
Witchhunter,
You do remember correctly, they were D-2. The Crossada's made by Bob Dozier were A-2 and James K. wanted a steel with closer to stainless properties. We decided on D-2 at RC-58, remember that the Crossada's were 1/4" thick.

Also remember that D-2 is used to cut other steels/metals in machine shops. It is a tool and die steel. D-2 is not brittle! If left at high hardness and ground too thin you will chip the edges and risk breaking the tip, but the Crossada's geometry is markedly thicker than my small edc knives.

Tom
 
Witchhunter,

This illustrates one of my points that the key to a high performance knife is selecting the right steel , with the right heat treat and the right geometry for the intended job.

Tom
 
Do you consider a crappy
edge one that can "POP" free standing arm hair?

Don't know, how coarse is your arm hair, can the same edge cleanly slice single ply toilet paper, push cut it, push cut newsprint at 4"+ from the point it is held? Can you push the edge into the skin of a grape without the grape moving? Can it cut baisting thread with < 65 g of force?

If you can't get a good edge on D-2 maybe it is your sharpening style or stones. A large extra fine diamond hone and a fine ceramic rod are all that are needed to get a hair popping "micro serrated" edge.

Yeah, the grindability of D2 is really low which is why the poor edge started, it takes so much longer to hone so it never actually gets finished in mosts cases people complain about it. I don't think you need anything special though, I have sharpened high carbide steels, even vanadium ones, on $1 hardware stones and sliced 3/8" manilla hemp on a 2" draw with < 5 lbs of force.


I know you know I can grind them as thin as you or anyone else could want!

Yes sure, thinner than I can easily, but now put a high polish on the D2 edge and use it for push cutting and compare that to even 1095 at the same configuration. But yeah, if you want aggressive slicing performance then D2 does well. I noted years ago there is a self sharpening effect with coarse steels as they chip out at the edge and it increases the sawing ability. Have you tried CPMD2? The P/M process will actually improve the wear resistance and edge stability (and even corrosion resistance).

I feel an edge in the .015-.020 range is nice and thin and easily sharpened and much stronger. It is also a big performance jump in geometry than most production knives out there.

It is way stronger, it is about 50 times more rigid than an edge at 0.005" thick, that gives a lot of room for sloppy use if that is what is needed. Edge stiffness is cubic with thickness so even small changes are a huge influence. The really bad thing is that the gain in cutting performance is actually smaller than linear so you have to trade huge durability for small gains in cutting ability.

As for most production knives, well yes if you compare to tacticals, but it isn't hard to find production knives at less than 0.010"/10 degrees. Just get an Opinel or Mora. These are clearly intended for just cutting though, no twisting of the edges, not something you would try to pound through a thick section of bone.

Have you broken a piece out of the edge on a 0.020" thick to see what it takes cutting wise? I don't think that would break apart even impact cutting violently through sheet metal with a hammer. What kind of problems were you getting with the <0.015" knives, I would have assumed the customer base is fairly selective at your price range.

-Cliff
 
Wow- nothing livens up a thread like when Cliff posts in it!:D

Seriously, thanks to all who have contributed here, I am learning way more than expected. I can't wait until I get a belt sander and start trying some thinner edge angles- even though it won't be on my Dozier!

with Sorg's regular D2 blade it took 2046 cuts on 3/8" hemp just to reach 20 lbs, good luck on ever reaching 30 lbs. I think that is actually an underestimate as the last thousand cuts I was sloppy. I always wanted to repeat that to get a better performance estimate, but the desire is not that strong to do another 2000 cuts, plus I think I need 4000 to really reach 20 lbs with proper technique. -Cliff

That is exactly why I got the Dozier- and it does slice! I really have no intention of "abusing" that knife as it's one of my thinner blades, but I will feel more confident with the 710.

I now feel totally under-equipped as to the thinness of my blades :( . I think I'll re-read this thread- too much good stuff to get in one gulp!
 
For what it's worth, I'm the one that brought up Swamp Rat's D2 knives being tougher than D2 is normally thought to be. I was responding to the original post that seemed to be asking "Is D2 an inherently brittle material?" Now that I re-read the original post, he seemed to be more asking about the two specific knives he mentioned. mea culpa


For what it's worth, here's the thread on the D2 Swamp Rats.

http://www.bladeforums.com/forums/showthread.php?t=322561
 
MVF, that extreme performance with the Sorg was with the edge configuration I described to Sodak, not a typical Dozier profile. The edge on the Sorg was serrated on two levels, it had large macro-teeth that you could see by eye and each of these teeth were microserrated. Imagine something like a Spyderco serraton pattern with a Cold Steel serration pattern super imposed on all of the teeth.

-Cliff
 
Don't know, how coarse is your arm hair, can the same edge cleanly slice single ply toilet paper, push cut it, push cut newsprint at 4"+ from the point it is held? Can you push the edge into the skin of a grape without the grape moving? Can it cut baisting thread with < 65 g of force?


-Cliff

Cliff I think this is more related to Geometry of the blade than the actual sharpness of the edge.... Right?

Tom
 
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