question about D2 steel.....................

A

anonymous

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Aug 23, 2003
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a few knifemakers whose work i admire use D2 steel almost exclusively. i'm interested in what the benefits/characteristics of D2 are - from a knifemaker's perspective. it's been fruitless researching this subject through steel companies, because they don't necessarily have knives in mind regarding the subject of D2.

here's some data i found on cryo treatment of various steels, showing that d2 was the most receptive (Source: Dr. R.F.Barron, Louisiana Tech University, Ruston, Louisiana, USA).

ASIS No....Alloy....wear resistance (%)
D-2........430.......817%
S-7........315.......500%
A-2....................560
52100.................420%
O-1....................418%
A-10...................264%
M-1....................225%

could this be one of the reasons for the d2 preference among some makers?

someone please educate me.
 
Are those numbers % improvement?

Let's give wear resistance a number (I'm making these numbers up) And Let's say no-cryo

CM 154 is 12
D2 is 3

Now let's say that with cyro you get

CM 154 is 14
D2 is 8

Well then CM154 got 16%, and D2 got 167%. However, it still wouldn't be as wear resistant as CM154. So, % improvement doesn't mean it's better. From your numbers I don't know if D2 is more or less wear resistant than 52100. It just improved more.

From the metal gang, I understand that properly treated D2 doesn't need cryo. (Don't shoot the messenger, I got that from the Pacific Heattreat)

Is the % improvement because the steel really responds in all cases or is the cryo covering up a bad hardening job?

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After all that gobbled-gook, I think the preference with D2 is the balance between corrosion resistance and toughness. It's almost a stainless steel, but still classified as non-stainless.

There are also issues like machinability. Hate to say it, but that is a consideration for knife making. There are steels with incredible edge holding abilities, but makers avoid it. You don't find many knifes in CPM10V. So steel choice is a balance game.

I've made a couple of D2 knifes. I like it. Is it better than S30V? Is it better than 52100? Depends on the application, as they say.

Hope that gives you some food for thought.

Steve
 
Originally posted by itrade
After all that gobbled-gook, I think the preference with D2 is the balance between corrosion resistance and toughness. It's almost a stainless steel, but still classified as non-stainless.

There are also issues like machinability. Hate to say it, but that is a consideration for knife making. There are steels with incredible edge holding abilities, but makers avoid it. You don't find many knifes in CPM10V. So steel choice is a balance game.

I've made a couple of D2 knifes. I like it. Is it better than S30V? Is it better than 52100? Depends on the application, as they say.
Click to expand...
thanks for the feedback steve. and yes, i believe the data was referring to improvement percentage.

feel free to drop some more knowledge about your experiences with working with various steels - in terms of toughness, edge holding, etc.
 
Some very knowledgeable people would argue with those percentages of improvement. There has been several threads to that effect.

D2 is a very wear resistant steel due to several factors including Carbon, Chromium, Vanadium and Molybdimum contents. Many people will argue vehemently that 154CM/ATS 34 does not have as much wear resistance as D2, much less more. Most specs that I have seen and my experience favor D2 in the comparison. S30V however, is another matter. It will out perform all of the above and many more besides.

This being said, I still use D2 along with S30V.
 
I like D-2 steel, just as I like 440C and RWL-34 in certain circumstances. It is quite wear resistant, even in the annealed state and can be a bugger to grind - it eats up a lot of belts and when drilling, you have to go slow and use lots of coolant / oil. I say that because I haven't used any of the CPM's yet, so I can't compare. Personally, I am now finding that for all the difficulty in working the stuff, it doesn't have the fine-ness in the edge and stain resistance of RWL-34. And I find that edge holding is pretty similar.

I think D2 has a different sort of edge due to the grain structure. It tends to be quite coarse / large and many people who polish their blades complain of an "orange-peel" appearance on the surface. The knives I have made with D2 are more difficult to get a fine shaving sharp edge working well, but even when they can't shave hair, the edge still cuts and cuts and cuts. It has an almost "rippy" quality to it which some poeple like for meat and game processing.

My 2 cents. Jason.
 
I dont think D2 steel is worth the trouble. It was invented around the the time of WWI and a lot has been done in terms of metalurgy since then. I started making knives from D2 and certainly they cut, but the reasons the powder metal steels were developed is becasue they are better. Steels like CPM s90v make an unbeatable sporting knife. In my opinion D2 has all the disadvantages of the PM steels - difficult to work and hard on tooling as well as being rather expensive - and it lacks the performance.

For carbon steel knives I like and use M2 HSS hardened to around RC63. The blades are extremely fine grained and cut and cut and cut. Brittelness is not a factor for smaller sporting blades. M2 is a dream to grind when soft and hardened it is very predictable and can take high temps without loosing hardness. I now have a gunsmith who hand hot blues the blades for me and that helps some with rust.
 
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