Chrome Vanadium Steel

[kootenay joe]

Some knives such as older Camillus Sta-Sharp knives, some more recent Case knives, etc. have blades made of "Chrome Vanadium" steel. Looking up "Chrome Vanadium" i find: "Both chromium and vanadium are added in order to improve the mechanical properties of the steel, hardness, strength and wear resistance." It is not rust resistant.
This sounds like "C.V." is not just one steel but a 'family' of steels all of which have Cr. & V. added. Hence all steels called "C.V." are not the same and therefore will not perform the same. I find this confounding for how can you know what exactly you have in a C.V. knife blade ?
Are any of the knife steels denoted by numbers a C.V. steel ? e.g. 1095, 1070, 5160, 52100, etc ?
Are any knife manufacturers using CV steel currently ?
I hope the replies will help clear up my confusion regarding C.V. steel.
kj

[philco]

Roland I'm no expert on blade steels but I do know that Case makes numerous knives that are stamped CV on one of the blades. They do not indicate what specific steel they are calling CV. If I'm not mistaken, GEC makes some of their knives with 1095 steel. If I'm wrong someone please correct me on this.

[kootenay joe]

Yes most of GEC knives are 1095. So Case still uses CV steel but if another knife company also uses C.V. steel it could be a different steel.
Do you agree that C.V. is a 'family' of steels ? and that 1095 is not a C.V. steel ?
kj

[edge213]

Chrome Vanadium is just the name for any given alloy used currently in Case knives.

They don't exactly announce when the the steel changes.

Late 90s early 2000s CV was based on 1095 later it changed to 1086 with trace amounts of vanadium and chromium.

[terryl308]

Yes most of GEC knives are 1095. So Case still uses CV steel but if another knife company also uses C.V. steel it could be a different steel.
Do you agree that C.V. is a 'family' of steels ? and that 1095 is not a C.V. steel ?
kj

Your right KJ. 1095 is not a Chrome/vanadium alloy steel. It would be called a "plain carbon non alloy " steel. The "10" series is a plain carbon steel with last 2 numbers being the carbon content (.95 percent carbon). The CV series would be the number 6XXX. I use some 1080 carbon steel (.80% carbon). I also use a lot of O-1 which contains .90 carbon, .50 chrome, 1.00 manganese, and .50 tungsten. I have never used CV so I don't know what the element make up is except that it has carbon, chrome, and vanadium in it, and probably more trace elements. Terry

[KnifeSlinger#81]

Chrome Vanadium is just the name for any given alloy used currently in Case knives.

They don't exactly announce when the the steel changes.

Late 90s early 2000s CV was based on 1095 later it changed to 1086 with trace amounts of vanadium and chromium.

Yes that is correct.



Chrome vanadium is not a steel type itself, rather it's some elements put into a steel. CV is just a marketing name for case.

[kootenay joe]

Thanks for this help but more is needed because i still am not clear about "C.V." steel.
Quote: "CV is just a marketing name for case." Sears Sta-Sharp knives made by Camillus in 1940's ? often had a blade etch "Chrome Vanadium".
Quote: "Late 90s early 2000s CV was based on 1095". How did this happen ? Did Case contact the steel supplier and say "Hey man could ya add a little Chromium & Vanadium to our next shipment of 1095" ?
Seems like any steel could be made into C.V. steel by adding these 2 elements ?
So C.V. blades from one knife manufacturer could be a different steel from the C.V. blades from another knife manufacturer.
I am thinking that "C.V. steel" is similar in scope to the term "pickup truck" which tells you the basic configuration of your vehicle but nothing about size, horse-power, drive train system, etc. ?
kj

[Mumbleypeg]

What little I know about this topic comes from when I toured the Case factory about 10 years ago. During the tour we saw large rolls of steel stock in the warehouse area near the receiving dock. I asked the tour guide, long-time Case employee Whitey Peterson, if their CV steel (my favorite) had changed any since the Tested XX era. His reply was that it is the exact same steel and has not changed. He added that the formula and the supplier is proprietary to Case.

That's it. Probably not esoteric enough to adequately answer your question. Your analogy to pick-up trucks is probably right. The buyer has to decide whether they like Ford or Chevy better. If a knife has chrome vanadium steel blades, exactly what the content is depends on the maker. If the maker cares about their reputation for quality, or just sells on price, probably can help guide the buying decision.

Ken

[kootenay joe]

A steel mill would have supplied Case with their CV steel and it might be a proprietary formula just for Case. I wonder if Camillus was supplied with the same C.V. steel for the Sta-Sharp knives etched "Chrome Vanadium" ? or was a different steel used to make C.V. for Camillus ?
If you wanted to order C.V. steel now, today, would you be asked "which one" ?
kj

[bestgear]

Here's a link to a knife steel composition chart: http://knifeinformer.com/knife-steel-composition-chart/

Maybe this will help (or confuse )

[terryl308]

KJ, I have contacted Crucible Steel and asked them if they had any info on CV steel used by Case and got a response already, but they didn't supply case with that alloy, he forwarded my email to Niagara Specialty Metals and I'll let you know what they said. Terry

[SolWarrior]

My personal belief about 1095 steel & CV is that IF CV has been added to 1095 high carbon steel it is no longer 1095 high carbon steel and thus will not have the same characteristics as a CV steel in any reasonable amount in any steel. CV steel does resist rust but nothing lasts forever. CV like "stainless" will eventually breakdown while 1095 high carbon will rust much faster if not taken care of regularly and properly. The plus side to me is the performance and patina(!) that 1095 high carbon steel forms with time on HOKs. It's awesome and nothing else like it!

From wikipedia:

Chromium-vanadium steel refers to steel alloys incorporating carbon, manganese, phosphorus, sulfur, silicon, chromium, and vanadium. Some forms can be used as high-speed steel.[1] Chromium and vanadium both make the steel more hardenable. Chromium also helps resist abrasion, oxidation, and corrosion.[2] Chromium and carbon can both improve elasticity.[3]

[kootenay joe]

Thanks Terry. We will see what Niagara says but the exact formula for Case's steel might be secret.
Regarding rust resistance, on a site called Quora, i found this in regards to CV steel:
"Last, it's worth noting that a lot of people immediately yell "corrosion resistance" when they see chromium, however in this case the chromium content is so low that corrosion resistance is completely negligible. In common application like wrenches, the component may be plated/coated with a layer of nickel."
The main reason for adding Cr & V is:
"Both chromium and vanadium are added in order to improve the mechanical properties of the steel, hardness, strength and wear resistance. Both chromium (0.8 - 1.1 %) vanadium (0.18 %) are ferrite stabilisers [that's the magnetic form of steel with body-centered structure]. This means that they make quenching of the steel much easier [you don't have to use oil, air is sufficient!] "
From this i would say that CV steel has no stainless properties.
kj

[kootenay joe]

Tom, that steel chart is MOST helpful.. For example it lists 1095 and 1095CV which has Cr 0.4-0.6% & V as 0.15-0.25%.
The stainless steels with CV like CPM-20CV has 20% Cr & 4% V.
The amount of Cr & V in 1095CV is too little to make it rust resistant.
kj

[Mumbleypeg]

The amount of Cr & V in 1095CV is too little to make it rust resistant.
kj

Correct. In fact it says Case CV steel is not rust resistant on the Case web site, and also on the paperwork provided in the box with the knife. http://www.wrcase.com/case_college/blades_steel/

Ken

[SolWarrior]

The amount of Cr & V in 1095CV is too little to make it rust resistant.
kj

Correct. In fact it says Case CV steel is not rust resistant on the Case web site, and also on the paperwork provided in the box with the knife. http://www.wrcase.com/case_college/blades_steel/

Ken

That's probably true with regards to Case's "CV" in particular but why not just show some CV steel knives from different makers. After all, as they say "a picture is worth a thousand words" Here's Roland's (Kootenay Joe) ex-knife in CV steel which I believe sparked this discussion to begin with. It's from the late 1940s and it looks spotless.

[Quick Steel]

Following this interesting discussion I recalled reading long ago that for a steel to be stainless it had to have at least 14% chromium. But I just looked up in Scientific American in which it says. "...In fact, all stainless steels by definition contain at least 10 percent chromium."

I hope this is at least mildly relevant to someone.

[SolWarrior]

Vanadium also aids in preventing oxidation and thus corrosion.

[Colonel26]

I like CASE CV. I also like 1095, although the 1095 is often harder to sharpen, it does time seem to hold an edge a tad longer than CASE CV.

As to rustresistance, I seem to be able to rust a CASE knife quicker than other maker's 1095. I don't know why, but that's my experience. YMMV.

CASE CV is still the standard by which I judge all other knife steels. Some perform better, and others worse. But it is still the standard I use because to me, it's just that good.

[kootenay joe]

Felix, lovely Sta-Sharp whittler you posted ! And spotless at about age 75 or more years. But i think it has had a light buff as the etch is not at full 'strength' but there is not even a hint of pitting so if any oxidation was removed, it was very superficial, more so than the etch.
I bought that knife from Mr. Claussen, a well known knife purveyor (& author "Sheffield Exhibition Knives") and was told it came from the Camillus factory knife display.
kj

[SolWarrior]

Felix, lovely Sta-Sharp whittler you posted ! And spotless at about age 75 or more years. But i think it has had a light buff as the etch is not at full 'strength' but there is not even a hint of pitting so if any oxidation was removed, it was very superficial, more so than the etch.
I bought that knife from Mr. Claussen, a well known knife purveyor (& author "Sheffield Exhibition Knives") and was told it came from the Camillus factory knife display.
kj

"Felix, lovely Sta-Sharp whittler you posted !" Why did you sell it?!? That was the cream of the crop to me. But sadly it was CV steel and I'm a 1095 high carbon steel guy. I wonder who buffed it if Mr. Claussen is apparently very knowledgeable and it came from the Camillus factory knife display?

I like CASE CV. I also like 1095, although the 1095 is often harder to sharpen, it does time seem to hold an edge a tad longer than CASE CV.

As to rustresistance, I seem to be able to rust a CASE knife quicker than other maker's 1095. I don't know why, but that's my experience. YMMV.

CASE CV is still the standard by which I judge all other knife steels. Some perform better, and others worse. But it is still the standard I use because to me, it's just that good.

Wade, I've never owned a Case knife but it sounds to me (based on what I read on this thread that they rust and so on) that the CV blades they make hardly have any chrome vanadium. Maybe yours was made with 1075 or lower steel if 1095 takes longer to sharpen? With CV in it that should make any steel harder and so tougher to sharpen, IMHO.

[Colonel26]

Felix, lovely Sta-Sharp whittler you posted ! And spotless at about age 75 or more years. But i think it has had a light buff as the etch is not at full 'strength' but there is not even a hint of pitting so if any oxidation was removed, it was very superficial, more so than the etch.
I bought that knife from Mr. Claussen, a well known knife purveyor (& author "Sheffield Exhibition Knives") and was told it came from the Camillus factory knife display.
kj

"Felix, lovely Sta-Sharp whittler you posted !" Why did you sell it?!? That was the cream of the crop to me. But sadly it was CV steel and I'm a 1095 high carbon steel guy. I wonder who buffed it if Mr. Claussen is apparently very knowledgeable and it came from the Camillus factory knife display?

I like CASE CV. I also like 1095, although the 1095 is often harder to sharpen, it does time seem to hold an edge a tad longer than CASE CV.

As to rustresistance, I seem to be able to rust a CASE knife quicker than other maker's 1095. I don't know why, but that's my experience. YMMV.

CASE CV is still the standard by which I judge all other knife steels. Some perform better, and others worse. But it is still the standard I use because to me, it's just that good.

Wade, I've never owned a Case knife but it sounds to me (based on what I read on this thread that they rust and so on) that the CV blades they make hardly have any chrome vanadium. Maybe yours was made with 1075 or lower steel if 1095 takes longer to sharpen? With CV in it that should make any steel harder and so tougher to sharpen, IMHO.

Maybe, maybe not. There are many many variables when it comes to hardness. The steel "recipe" is just one of them. How was the blade heat treated. What was the quenching, tempering process? How many times was it tempered? Those are more important than the difference between 1080, 1095, CV or whatever other recipe.

CASE in point (pun intended), in my opinion the XX and early dot era steel was harder than now. CASE wouldn't have to change their steel recipe, but they could adjust their heat treating process to change the properties of the steel.

In older knives, I've been told that back in the day CASE, Camillus, Western etc... all used basically the same steel. But they all had their own little tricks with the heat treating.

[Tsar Bomba]

Some great information, everyone, and a better knife steel chart than I've been using!

The only addition I can offer is that years ago, long before the advent of super steels, carbon steel blades were routinely hardened to lower Rockwell numbers, e.g. RC 52-53. That's why we think of the old steels and marvel at how quickly they take an edge off a stone versus having to swipe at a DMT endlessly with ATS-34 or D2. It is entirely possible that more modern/better heat treatments give the same CV better edge retention than the "standard" of 1095 we're all used to, meaning they will also take longer on the stone (i.e. "harder to sharpen").

Short of that, I'm sure a lot of the differences we notice and value come down to the actual content of the steel. But it's important not to discount the role HT plays in the final product.

[terryl308]

Got the following response from Niagara, "We make a grade called CPM20-CV, but do not believe we have sold this alloy to Case. Can't tell you for sure what grade is referenced, but this is one grade that might be considered:1095CV.
C:0.95-1.10;V:0,15-0.25; Cr:0.40-0.60; Mo: 0.06; Mn: 0.30-0.50; Ni:0.25; P:0.025; Si 0.15-0.25; Maker: Sharon Steel-US Notes: 1095cv- Based on 1095 steel, with the addition of small amounts of V,Mo, Ni, Cr. Improved wear resistance and toughness compared to 1095. Ka-Bar and Bark river use this steel in their knives. Ka-Bar under 1095 Cro-Van name and Bark River as 50-110B. Developed by now defunct Sharon Steel. Best Regards, Jeff Rich NSM.
That's all I have for now, Terry

[kootenay joe]

What a fine reply. I am impressed that this steel company employee took the time to send you a detailed message.
kj