CPM steels different than others?

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KennyB

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Jan 19, 2010
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What's the deal with CPM-D2 versus D2 and CPM-S30V versus S30V? From what I've gathered CPM is some kind of steel company, but so does this mean that "S30V" and "D2" are just generic brands of it or something along those lines?

Just want to get the full story.
 
CPM is a process, proprietary of Crucible company.
CPM D2 tells that AISI D2 steel was made using CPM process.
CPM S30V is Crucible proprietary steel.
D2 is AISI standard name of the tool steel.

Check the steel chart linked below, for compositions, name references and maker info.
 
Gator97 said:
CPM is a process, proprietary of Crucible company.
CPM D2 tells that AISI D2 steel was made using CPM process.
CPM S30V is Crucible proprietary steel.
D2 is AISI standard name of the tool steel.

Check the steel chart linked below, for compositions, name references and maker info.
Click to expand...

So does that mean when Benchmade just says a blade is S30V, they use their own process instead of CPM's, or is it all the same?
 
Gator97 said:
CPM is a process, proprietary of Crucible company.
CPM D2 tells that AISI D2 steel was made using CPM process.
CPM S30V is Crucible proprietary steel.
D2 is AISI standard name of the tool steel.

Check the steel chart linked below, for compositions, name references and maker info.
Click to expand...

Hmm , I think you forgot the link . ;)

1234,,:)
 
KennyB said:
So does that mean when Benchmade just says a blade is S30V, they use their own process instead of CPM's, or is it all the same?
Click to expand...

I think it means only CPM makes s30v. So Benchmade uses CPM steel in those blades.
 
CPM is Crucible Particle Metallurgy
Crucible is the company
particle metallurgy is the process
Hitachi makes ZDP-189, Takefu makes SGPS, Bohler makes M390, etc., all by particle metallurgy. Other companies have PM steel/process names like MicroMelt or SuperClean.
Some steels formulations are only possible because of PM, since the alloy content is so high, like ZDP-189 or S125V. Some steels have the same alloy content as wrought, but the PM process improves properties, like CPM D2 or RWL-34.
 
S30V, S90V, 3V, and a laundry list of others are CPM products, go to CPM's site to discover all the other steels they offer. Its a better way to get very pure steels that offer advanced abilities in cutting and sharpening. I guess a better description would be to call them "clean steels".
 
long story short, the cpm process relates to the alloy metal being atomized into very small particles, then cooled. these particle are then compressed and forge welded into sheets or stock.
the process gives more uniformity to the grain structure.
it's way more involved than what i descibed.
hope this helps.
later,
don
 
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To answer KennyB's question...Benchmade doesn't make their own steel. Any knife steel made in S30V comes from the Crucible company.
 
jkarp_53 said:
To answer KennyB's question...Benchmade doesn't make their own steel. Any knife steel made in S30V comes from the Crucible company.
Click to expand...

This is correct, AND it is also true that the heat treat is not done by Crucible, so different knife companies' S30V's can exhibit different performance characteristics despite the S30V steel all coming from a single source.
 
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KennyB said:
What's the deal with CPM-D2 versus D2 and CPM-S30V versus S30V? From what I've gathered CPM is some kind of steel company, but so does this mean that "S30V" and "D2" are just generic brands of it or something along those lines?

Just want to get the full story.
Click to expand...

There is special process - Particle Wetallurgy, when liquid steel turns to powder (1-2 micron particle) using high pressur neutral gas jet then compressed into blanks under high pressure and temperature.

This allows to produce steel with exotic composition which can not be done regular way. This way special steels were made (by Crusible only):
CPM S30V, CPM S90V, CPM 10V, CPM 3V ...
Otherwise I guess some component of alloy get crystallized - aggregated together making steel brittle.

Crucible also produce steels regular way with non exotic composition. Some of them are standard - D2, M2, M4. Some of them only Crucible do - 154CM (this one have analogs ATS-34, RWL34 but not exact same).

Now steel with same composition can be processed using Particle Metallurgy method. Advantages of that is that steel get powdered to 1-2 micron particles and so get it finer then it became regular way. Some steel get benefit from this. This way we have D2 and CPM D2, 154CM and CPM 154.

But CPM S30V only can be produced by particle metallurgy so there is no such thing as S30V - only CPM S30V.

Usually you may expect better performance from regular steel processed by particle metallurgy - but it is not a rule.

Many other companies doing particle metallurgy. For example European RWL-34 is PM steel. Damasteel produce damascus blanks mixing different steel powders in same blank...

good video on the subject:
http://www.youtube.com/watch?v=Hs5sq79degg

Thanks, Vassili.
 
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