D2 and CPM M4

B

Beanman13

Joined
Feb 18, 2006
Messages
124
I'm just curious about people's experiences with D2 and CPM M4 steels. I have both and like both. For me both sharpen with equal ease on DMT stones and strops. I'm just curious to hear from others if either wins out over the other and for what reason.

For me CPM M4 on the mini Ritter Grip wins out. Seems to take a finer edge more readily and hold it longer. It's also ground thinner than my D2 blades so maybe that's part of it. From the properties I've read CPM M4 is tougher, stronger and more wear resistant. I haven't put either to those sorts of test so I'm on the sidelines for that discussion. The primary reason for this post I suppose is that I get the feeling from most literature and posts that CPM M4 will outperform D2, yet numerous knives in D2 are in continued production. There's got to be a good reason for it. Maybe it's price point, or availability, or some combination of factors.
 
Thanks Hardheart. So from a performance standpoint would you always pick CPM M4 over D2 I assume?
 
I like M4 but it depends on who does the heat treat. If it is Benchmade I think I like their D2 better than their M4. Their M4 will get screaming Sharp pretty easy but the D2 seems to hold an edge longer. When M4 is run harder like Spyderco does then I would probably pick the M4.

My EDC that is in my RFP every single day is a Benchmade Rift in M4. It performs well but doesn't hold an edge as long as some of the other knives I carry in addition to the Rift.
 
"For me CPM M4 on the mini Ritter Grip wins out. Seems to take a finer edge more readily and hold it longer."
+1
I have both D2 and M4 from Benchmade and agree with your findings Beanman13
The D2 edge is very good just not as fine or as razor sharp as it is on my M4 and M2 blades.
Edge retention is very close.
 
Knarfeng, I recall reading the post you linked. Thanks for the information and a good read. I value your work and that of those who are doing similar studies. I have a question you might know the answer to. The CPM M4 HC used in the GB, does it also include the large bar (HS) mod? I know they said it was for large bar, but I wasn't certain where flat sheet comes in with regards to that modification to the alloying elements.

FlaMtnBkr, you might be right on for daily use. I honestly wouldn't be able to say because I often do something ignorant to kill a spot on the edge that prompts me to resharpen. What blades do you carry that outlast the Rift?

The Spyderco Gayle Bradley is on my Christmas list so I'm hoping to get a real-world feel for the HT differences. Given I'd be comparing a hollow ground and flat saber ground blade (I think... I get the nuances mixed up sometimes), so the grinds may have an effect, but it should be negligible unless the GB is a lot more obtuse than I anticipate.
 
I have the Benchmade 806 CPM M4, and the Spyderco Paramilitary CPM D2(I have owned a 806D2 and a Military CPM D2 in the past).
I find the Paramilitary slices better because of the thinner blade, but they both hold an edge for awhile, and I try not to let them get dull. I will sharpen them on my Spyderco ultrafine benchstone every few weeks(just a few strokes). I find that my edge is hair popping sharp, but still has a bite like it is serrated. Great for cutting out a coupon, or slicing up cardboard boxes, the CPM D2 and CPM M4 can do both with ease, and for a long time. Very impressive.
Years ago before there was a Bladeforums, ATS-34 was the steel to have. It is hard to anticipate what steel will be "THE ONE" to have in another ten years.



--Jason--
 
It would be interesting to see CPM-M4 in the Spyderco Gayle Bradley pitted up against Dozier D2:thumbup:.
 
Frank thanks for the response. I figured it couldn't hurt to ask and if anyone knew you'd be the guy.

Noctis I'd have to agree. I've read that Dozier is the king of D2. If he's got the HT dialed in that well it'd be really neat to see how it fares. Do you have anything in Dozier D2?
 
Noctis3880 said:
It would be interesting to see CPM-M4 in the Spyderco Gayle Bradley pitted up against Dozier D2:thumbup:.
Click to expand...

unless bob sprinkles pixie dust on the steel before heat treating, my money is on the CPM-M4 (saying that the edge geometry is similar).

bob's D2 is ingot steel, the CPM-M4 is a powdered steel

D2 has:
1.55% carbon
11.5% chromium
0.9% molybdenum
0.8% vanadium

CPM-M4 has:
1.42% carbon
4.0% chromium
5.25% molybdenum
5.5% tungsten
4% vanadium
 
Noctis3880 said:
It would be interesting to see CPM-M4 in the Spyderco Gayle Bradley pitted up against Dozier D2:thumbup:.
Click to expand...


That wouldn't be an even comparison, apples to oranges.

Custom to production knives ect....

Notice I didn't mention the steels as it doesn't matter what the steels are as direct comparisons between Custom and production knives are insane.

That's also most of the cause of a lot of the bad information about steels in general because the Custom knives will out perform the production knives by a huge margin most of the time depending on the maker.

That margin is usually big enough that the steel doesn't matter. ;)

So one would be comparing knives, not steels in that comparison.
 
Last edited:
David Martin said:
Ankerson--Hear, hear! DM
Click to expand...

There is just way too much of that going around and has been for a long time.

Comparing Customs to Production knives is crazy especially if the Custom Maker does their own heat treating like most of the top Custom guys do.

Not even on the same planet.

Comparing Production knives to Custom knives by makers like Ed Fowler, Phil Wilson, Bob Dozier, Jerry Hossom and other top makers is so insane it's funny.

That's not a shot at the Production makers, what I am saying is the Customs are really that good.
 
Last edited:
I suppose I shouldn't be surprised. I imagined a well heat treated blade from a custom maker might outdo a higher alloyed production blade but I didn't think it would go as far as apples and oranges. For me, anytime there's a comparison I'd want to know which maker whether it be custom or production, the hardness if possible, and what sort of section is being used. Knowing things like this help me frame the data in my mind.

Ankerson in your experience is it the heat treat or the blade grind or both that accounts for the majority of the disparity? I know a lot of custom makers tweak HT, use quench plates, cryo etc. I'm just curious where most of the difference is coming from.
 
Beanman13 said:
I suppose I shouldn't be surprised. I imagined a well heat treated blade from a custom maker might outdo a higher alloyed production blade but I didn't think it would go as far as apples and oranges. For me, anytime there's a comparison I'd want to know which maker whether it be custom or production, the hardness if possible, and what sort of section is being used. Knowing things like this help me frame the data in my mind.

Ankerson in your experience is it the heat treat or the blade grind or both that accounts for the majority of the disparity? I know a lot of custom makers tweak HT, use quench plates, cryo etc. I'm just curious where most of the difference is coming from.
Click to expand...

It's a lot of everything the whole knife, design, blade geometry, edge geometry, heat treating, tempering ect.

A lot of these Custom Craftsman have perfected their designs over years, sometimes decades of real world use out in the field ect.

Others Like Ed Fowler, Phil Wilson and Bob Dozier have perfected their Heat Treating and tempering processes over decades, combine that with highly optimized designs they make and well there you have it.
 
Execution from real world use has a lot to do with it but many little things. We may only make one or two shapes so they had better be tops in that area. Thanks, DM
 
You must log in or register to reply here.
Back
Top