Case's Chrome Vanadium vs. Carbon Steel?

hsherzfeld said:
Is there a difference between Case's chrome vanadium steel (CV) and their carbon steel (CS)?

I just bought a Case medium jack in amber bone and (according to the description on the big river site) CV steel. Well, on arrival it turned out to be carbon steel instead. I'm just curious if anyone knows what the difference between the two is. I have several Case knives in CV steel, but no others in CS.

Here's the knife in question:
Click to expand...
Hmmmm... Where's my soapbox. Ah. Here it is....

The formal AISI (American Iron and Steel Institute) definition of "Carbon Steel" is
"Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium [niobium], molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 per cent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."

So "carbon steel" only contains Iron, Carbon, a maximum of 1.65% Manganese, a maximum of 0.6%Silicon, and a maximum of 0.6% Copper,

I believe Case is using 1095 carbon steel. Here is the formal composition for that:
Iron, Fe98.38 - 98.8
Carbon, C0.90 - 1.03
Sulfur, S≤ 0.050
Phosphorous, P≤ 0.040
Manganese, Mn0.30 - 0.50

'"CV steel" was 1095 carbon steel with an additional 0.5% Chromium and 0.2% Vanadium. (I've seen certs for one of the lots. They were given to me by Steve Pfeiffer, BF member and noted authority on Case knife collecting. He obtained them from the fle room of the WR Case Company.)
--Chromium at that concentration is used to give a more even heat treat through the alloy, important for thicker blades.
--Vanadium at that concentration is used to generate a finer grain structure. This makes the alloy stronger.

In my opinion, CV takes an even finer edge than standard carbon steel. For a pocket knife blade, I don't know that you would notice any other performance differences.

Case CV does not have the same composition as Kabar 1095 Cro Van. But both are custom alloys made specifically for the Case and KaBar, respectively.

There was a discussion a few weeks ago in the General Forum about the change. Member Larrin Thomas, a PhD metallurgist who both developed the Magnacut alloy and works in the commercial steel industry, said he thinks that Case was unable to source CV in the US because the remaining US steel mills now only sell huge lots. CV was a custom alloy. To obtain it, Case would need to purchase the entire lot (called a "heat"). Case was not financially able to buy the tons of steel which would result if a US mill made a lot. Their other option would have been to source their steel from outside the US. Case decided to change to 1095, instead. KaBar had the same problem, but went the other direction and is now sourcing 1095 CroVan from Europe. I can understand that decision. In blades with the thickness of the ones made by KaBar, 1095 and 1095 Cro Van would not heat treat the same.
 
knarfeng said:
Hmmmm... Where's my soapbox. Ah. Here it is....

The formal AISI (American Iron and Steel Institute) definition of "Carbon Steel" is
"Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium [niobium], molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 per cent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."

So "carbon steel" only contains Iron, Carbon, a maximum of 1.65% Manganese, a maximum of 0.6%Silicon, and a maximum of 0.6% Copper,

I believe Case is using 1095 carbon steel. Here is the formal composition for that:
Iron, Fe98.38 - 98.8
Carbon, C0.90 - 1.03
Sulfur, S≤ 0.050
Phosphorous, P≤ 0.040
Manganese, Mn0.30 - 0.50

'"CV steel" was 1095 carbon steel with an additional 0.5% Chromium and 0.2% Vanadium. (I've seen certs for one of the lots. They were given to me by Steve Pfeiffer, BF member and noted authority on Case knife collecting. He obtained them from the fle room of the WR Case Company.)
--Chromium at that concentration is used to give a more even heat treat through the alloy, important for thicker blades.
--Vanadium at that concentration is used to generate a finer grain structure. This makes the alloy stronger.

In my opinion, CV takes an even finer edge than standard carbon steel. For a pocket knife blade, I don't know that you would notice any other performance differences.

Case CV does not have the same composition as Kabar 1095 Cro Van. But both are custom alloys made specifically for the Case and KaBar, respectively.

There was a discussion a few weeks ago in the General Forum about the change. Member Larrin Thomas, a PhD metallurgist who both developed the Magnacut alloy and works in the commercial steel industry, said he thinks that Case was unable to source CV in the US because the remaining US steel mills now only sell huge lots. CV was a custom alloy. To obtain it, Case would need to purchase the entire lot (called a "heat"). Case was not financially able to buy the tons of steel which would result if a US mill made a lot. Their other option would have been to source their steel from outside the US. Case decided to change to 1095, instead. KaBar had the same problem, but went the other direction and is now sourcing 1095 CroVan from Europe. I can understand that decision. In blades with the thickness of the ones made by KaBar, 1095 and 1095 Cro Van would not heat treat the same.
Click to expand...
Great information, Frank.
 
knarfeng said:
Hmmmm... Where's my soapbox. Ah. Here it is....

The formal AISI (American Iron and Steel Institute) definition of "Carbon Steel" is
"Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium [niobium], molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 per cent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."

So "carbon steel" only contains Iron, Carbon, a maximum of 1.65% Manganese, a maximum of 0.6%Silicon, and a maximum of 0.6% Copper,

I believe Case is using 1095 carbon steel. Here is the formal composition for that:
Iron, Fe98.38 - 98.8
Carbon, C0.90 - 1.03
Sulfur, S≤ 0.050
Phosphorous, P≤ 0.040
Manganese, Mn0.30 - 0.50

'"CV steel" was 1095 carbon steel with an additional 0.5% Chromium and 0.2% Vanadium. (I've seen certs for one of the lots. They were given to me by Steve Pfeiffer, BF member and noted authority on Case knife collecting. He obtained them from the fle room of the WR Case Company.)
--Chromium at that concentration is used to give a more even heat treat through the alloy, important for thicker blades.
--Vanadium at that concentration is used to generate a finer grain structure. This makes the alloy stronger.

In my opinion, CV takes an even finer edge than standard carbon steel. For a pocket knife blade, I don't know that you would notice any other performance differences.

Case CV does not have the same composition as Kabar 1095 Cro Van. But both are custom alloys made specifically for the Case and KaBar, respectively.

There was a discussion a few weeks ago in the General Forum about the change. Member Larrin Thomas, a PhD metallurgist who both developed the Magnacut alloy and works in the commercial steel industry, said he thinks that Case was unable to source CV in the US because the remaining US steel mills now only sell huge lots. CV was a custom alloy. To obtain it, Case would need to purchase the entire lot (called a "heat"). Case was not financially able to buy the tons of steel which would result if a US mill made a lot. Their other option would have been to source their steel from outside the US. Case decided to change to 1095, instead. KaBar had the same problem, but went the other direction and is now sourcing 1095 CroVan from Europe. I can understand that decision. In blades with the thickness of the ones made by KaBar, 1095 and 1095 Cro Van would not heat treat the same.
Click to expand...
That was an enjoyable and informative read, thank you!
 
knarfeng said:
Hmmmm... Where's my soapbox. Ah. Here it is....

The formal AISI (American Iron and Steel Institute) definition of "Carbon Steel" is
"Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium [niobium], molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 per cent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."

So "carbon steel" only contains Iron, Carbon, a maximum of 1.65% Manganese, a maximum of 0.6%Silicon, and a maximum of 0.6% Copper,

I believe Case is using 1095 carbon steel. Here is the formal composition for that:
Iron, Fe98.38 - 98.8
Carbon, C0.90 - 1.03
Sulfur, S≤ 0.050
Phosphorous, P≤ 0.040
Manganese, Mn0.30 - 0.50

'"CV steel" was 1095 carbon steel with an additional 0.5% Chromium and 0.2% Vanadium. (I've seen certs for one of the lots. They were given to me by Steve Pfeiffer, BF member and noted authority on Case knife collecting. He obtained them from the fle room of the WR Case Company.)
--Chromium at that concentration is used to give a more even heat treat through the alloy, important for thicker blades.
--Vanadium at that concentration is used to generate a finer grain structure. This makes the alloy stronger.

In my opinion, CV takes an even finer edge than standard carbon steel. For a pocket knife blade, I don't know that you would notice any other performance differences.

Case CV does not have the same composition as Kabar 1095 Cro Van. But both are custom alloys made specifically for the Case and KaBar, respectively.

There was a discussion a few weeks ago in the General Forum about the change. Member Larrin Thomas, a PhD metallurgist who both developed the Magnacut alloy and works in the commercial steel industry, said he thinks that Case was unable to source CV in the US because the remaining US steel mills now only sell huge lots. CV was a custom alloy. To obtain it, Case would need to purchase the entire lot (called a "heat"). Case was not financially able to buy the tons of steel which would result if a US mill made a lot. Their other option would have been to source their steel from outside the US. Case decided to change to 1095, instead. KaBar had the same problem, but went the other direction and is now sourcing 1095 CroVan from Europe. I can understand that decision. In blades with the thickness of the ones made by KaBar, 1095 and 1095 Cro Van would not heat treat the same.
Click to expand...
Wow, thanks to you and Steve for the info!
 
knarfeng said:
Case was unable to source CV in the US because the remaining US steel mills now only sell huge lots. CV was a custom alloy. To obtain it, Case would need to purchase the entire lot (called a "heat"). Case was not financially able to buy the tons of steel which would result if a US mill made a lot. Their other option would have been to source their steel from outside the US. Case decided to change to 1095, instead.
Click to expand...

So, Case, rather than using imported steel, switched to 1095.

I respect that.

A lot.
 
I'm a big fan of Case's carbon steels (particularly because all I have to do to keep them sharp is strop them) but I have noticed small differences that may be worth discussing (of course, this is all empirical data and your mileage may vary).

I have a few CS knives and they generally patina faster and darker (the coloration of the patina is deeper than with CV or 1095). I also find the steel to be softer than CV or 1095 proper (I am saying 1095 proper as Case now has knives that are stamped 1095 on the tang). CV seems to be the hardest to put a patina on, which may mean it is a bit more corrosion resistant. I've also found it to be a little harder than CS, and I am basing this off of the frequency of maintenance needed to keep the edge I want on them. 1095 is the best of the 3 when it comes to toughness and edge retention. It will patina about the same as CV, but with slightly different coloration. I generally cut the same stuff with all 3 of these steels, so although this is from my personal experience, I've sort of tested how quickly and how deeply they patina (I like how a slipjoint knife looks with some light patina on the blade). If you're going to use it for work and want to avoid a lot of maintenance, I'd say choose 1095 (as stamped on the tang), with CV being a very close 2nd. CS stamped knives, because (I believe) the steel is a bit softer, require more maintenance, and if you sleep on maintenance after using it can rust more quickly than the other two. I don't have a means of testing, but I would bet money that if their 1095 is 58-60 HRC (which is what google's AI "gemini" says) then the CS is probably 56-58. Again, your mileage may vary.
 
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