What is Cases CV steel?

[Spongebobby]

I realize it's great, and it sharpens easily, and holds a razor sharp edge for a decent amount of time if you strop it frequently. But what is the actual steel name? How hard is it on a rockwell scale? What is the actual composition? Thanks for help.

 

[Morrow]

I realize it's great, and it sharpens easily, and holds a razor sharp edge for a decent amount of time if you strop it frequently. But what is the actual steel name? How hard is it on a rockwell scale? What is the actual composition? Thanks for help.

It's an alloy based on 1085.

 

[JTR357]

I just read in Blade (spring 2012) that its 1095 with added chromium & vanadium.(page 35)

 

[Sword and Shield]

1095 CV, otherwise known as 10706-C. It's usually about 57RC.

 

[knarfeng]

I have a copy of a composition cert dated 1968 for alloy sold to WR Case by one of the major steel companies.

According to that cert, the alloy contained
0.86% Carbon
~% Chromium (less than 1%)
~% Vanadium (less than 1%)

That would make the composition on the order of 1085 CV.

Whether that is the current material or not, I do not know. I do know that I tested the hardness of a Case Sodbuster Jr. CV blade and found it to be 54HRC.

 

[Peter Parker]

The older I get the more I appreciate softer steels, even though a certain Co.'s CPM D2 with a 62 RC is still my favorite over all steel!

 

[SubSpace]

Could someone explain to me how CV is easier to sharpen than Tru-sharp, as I've seen claimed, yet holds an edge longer than Tru-sharp? I'm far from an engineer or scientist, but these two statements seem to contradict.

I personally cannot tell the difference in performance, although I do prefer CV when available as I like the "traditionalness" of it.

 

[Noddy]

oil cans

 

[knarfeng]

Could someone explain to me how CV is easier to sharpen than Tru-sharp, as I've seen claimed, yet holds an edge longer than Tru-sharp? I'm far from an engineer or scientist, but these two statements seem to contradict.

I personally cannot tell the difference in performance, although I do prefer CV when available as I like the "traditionalness" of it.

I dunno. I've done a side by side comparison of CV vs TruSharp, cutting manila rope. The CV held an edge a bit longer. I haven't noticed any difference in ease of sharpening. They are both super easy to sharpen.

 

[Quy4n8]

Sharpening a knife and dulling a knife through actual use are generally two different things. When sharpening, you are obviously trying to remove metal from the sides to form an edge. Stainless steels are stainless due to the addition of Chrome, which forms large, hard carbides that tend to stick together, thus making them generally harder to sharpen. You are using a harder and abrasive material to remove metal.

Dulling a knife through actual use most often does not involve materials that are harder than steel, you are not really removing metal from the edge. What happens more often is that the very edge gets rolled slightly, therefore dulling the knife. There are of course exceptions, such as cutting dirty rope or carpet, cutting cardboard (paper based products are suprisingly abrasive). A harder steel, say 62 Rc will hold and edge better than a softer steel of 57 Rc, not because you are wearing off the edge, but because it is more difficult to roll the edge.

Stainless is can be more difficult to sharpen because of the larger, hard chrome carbides. Plain carbon steel will hold an edge better with the proper heat treat because it is harder to roll the edge.

 

[jbmonkey]

I have a copy of a composition cert dated 1968 for alloy sold to WR Case by one of the major steel companies.

According to that cert, the alloy contained
0.86% Carbon
~% Chromium (less than 1%)
~% Vanadium (less than 1%)

That would make the composition on the order of 1085 CV.

Whether that is the current material or not, I do not know. I do know that I tested the hardness of a Case Sodbuster Jr. CV blade and found it to be 54HRC.

Sir, was the knife a modern one, you tested the hardness on, or an older one?

i had thought i read somewhere it was 1095 crovan, but you know the internet.....not always so accurate. anyone emailed case and asked recently? never mind i am off to do that myself, will report what i hear back.

also, and i almost forgot my manners....... interesting information about the 1968 case alloy specs. thank you, Sir, for sharing with us.

 

[Obsessed with Edges]

Could someone explain to me how CV is easier to sharpen than Tru-sharp, as I've seen claimed, yet holds an edge longer than Tru-sharp? I'm far from an engineer or scientist, but these two statements seem to contradict.

I personally cannot tell the difference in performance, although I do prefer CV when available as I like the "traditionalness" of it.

I firmly believe that edge-holding isn't a disparity, between CV and Tru-Sharp. I used to wonder about it, but not anymore. I have a lot of Case knives in Tru-Sharp, and have re-bevelled many or most of them. In terms of edge-holding, I don't see any significant difference. The one thing that might lead some to believe it doesn't hold an edge well, is Tru-Sharp's tendency to form and stubbornly hang on to wire edges. The wire edges themselves will mimic a sharp edge for a little while, then fold over to one side or the other, which obviously degrades cutting performance. That gives an impression that the steel dulls quickly. And it doesn't help that many of the Tru-Sharp blades come with wire edges straight out of the box (which is why I've gone ahead and resharpened most of mine, even when new). Once I realized what was really going on, I focused on making sure the wire edges are cleaned up completely, after sharpening. Once that's done, edge durability improves vastly, with Tru-Sharp. The CV steel doesn't seem to have as much of an issue with wire edges, so that makes sharpening it easier, with corresponding edge durability afterwards.

 

[pinnah]

How do you get rid of the wire edge?

 

[knarfeng]

Sir, was the knife a modern one, you tested the hardness on, or an older one?

i had thought i read somewhere it was 1095 crovan, but you know the internet.....not always so accurate. anyone emailed case and asked recently? never mind i am off to do that myself, will report what i hear back.

also, and i almost forgot my manners....... interesting information about the 1968 case alloy specs. thank you, Sir, for sharing with us.

umm...my friends call me Frank. (My father was "Sir". Never seemed to take with me.)

The blades I tested were recent.

I've done side by side testing of CV vs. Camillus 0170-6c (0170-6C, AKA Carbon V was essentially 1095CV) The Camillus performed noticeably better than the CV.

Couldn't get a hardness value on the Camillus because it was a two spring stockman. The blade tangs of two spring stockman blades have to be annealed so they can be crinked to fit. The tang is the only part of those blades with the proper configuration to get a hardness reading. When I have measured the hardnesses of blade tangs that I know were annealed, the measurement was in the low 40's.

 

[Obsessed with Edges]

How do you get rid of the wire edge?

More often than not, I usually use a flat ceramic hone. Check to see to which side the wire edge is leaning, then use the hone at a slightly elevated angle. I use a Spyderco 'DoubleStuff' hone on the medium side (akin to the brown rods on the Sharpmaker); that gets most of it. Then I'll usually finish with the fine. The stubborn nature of the wire edges usually means going back & forth, flipping the wire edge from side-to-side (and it will do this a while), until it is honed away or otherwise broken off. As it diminishes, decrease the pressure on the hone. Keep checking for the wire edge, by using your fingernail (sliding towards the edge), or do the same with the tip of a toothpick or a needle.

I emphasized a flat ceramic above, because it's more difficult to do this on round rods or using the corners of triangular hones (Sharpmaker). The small contact area on those will exert a lot of pressure on the edge, and sometimes will create more of a wire than remove it, if pressure is just a little excessive.

 

[pinnah]

More often than not, I usually use a flat ceramic hone. Check to see to which side the wire edge is leaning, then use the hone at a slightly elevated angle. I use a Spyderco 'DoubleStuff' hone on the medium side (akin to the brown rods on the Sharpmaker); that gets most of it. Then I'll usually finish with the fine. The stubborn nature of the wire edges usually means going back & forth, flipping the wire edge from side-to-side (and it will do this a while), until it is honed away or otherwise broken off. As it diminishes, decrease the pressure on the hone.

I use a Lansky system. Would the following make sense? Say the target edge angle is 20 degrees. Use the medium hone on both sides at 20 degrees until a burr forms. Then use the medium hone at 25 degrees using light pressure to remove the burr/wire edge. Then finish the edge with the fine hone at 20 degrees while avoiding bringing the edge to a burr. Finish with strop/steel yada yada...

This is definitely something I confront with more stainless blades and not with carbon steels as much.

 

[Obsessed with Edges]

I use a Lansky system. Would the following make sense? Say the target edge angle is 20 degrees. Use the medium hone on both sides at 20 degrees until a burr forms. Then use the medium hone at 25 degrees using light pressure to remove the burr/wire edge. Then finish the edge with the fine hone at 20 degrees while avoiding bringing the edge to a burr. Finish with strop/steel yada yada...

I think you could do it that way, but with a guided system, you might not necessarily have to. I also used a Lansky a lot, and I developed a habit of using the first hone to create the burr, then using the subsequent hones at progressively lighter pressure to very gently remove it, while 'sneaking up' on the true edge (as you put it, avoiding bringing it to a burr again). I didn't elevate the angle at all, but made sure to very closely examine the edge under magnification & bright light, to see my progress. By the time I'd reached the fine hone (purple ceramic in the blue holder), virtually all of the wire edge was gone. I'd use the fine and UF (white in yellow holder) to polish & refine the bevel. So long as the finishing stages are done at very, very light pressure, the wire edge/burr can be very gently filed away at the same set angle. A guided system makes this much easier, and produces an excellent result if done very, very gently.

When I'm just trying to remove the burr from an existing (factory) edge, and I'm doing it free-hand, I do find it simpler to do it at a slightly elevated angle, with the wire edge curled down into the hone. This method is geared more towards breaking the burr/wire off, by bending it back & forth, as opposed to filing it away.

This is definitely something I confront with more stainless blades and not with carbon steels as much.

Exactly. I think the extra chromium in stainless alloys is the biggest contributor to the added ductility, which is what makes the wires/burrs much more 'bendy' (without breaking off as easily). That ductility can be offset somewhat by heat treat to a slightly higher RC. The best example of that is comparing Case's Tru-Sharp (which is actually 420HC) to Buck's 420HC. Buck treats their blades to an additional 2 or 3 points on the RC scale, and I don't see the same stubborn wire edges on those blades (wires/burrs break off a bit more easily). Additionally, most of the popular carbon steels, like 1095 and CV, have a higher carbon content (above 0.80% carbon) than a lot of the common 'high carbon' stainless steels (around 0.50% carbon), which acts to make the steel less ductile (slightly more brittle), which therefore reduces the wire edge issues.

 

[jbmonkey]

umm...my friends call me Frank. (My father was "Sir". Never seemed to take with me.)

The blades I tested were recent.

I've done side by side testing of CV vs. Camillus 0170-6c (0170-6C, AKA Carbon V was essentially 1095CV) The Camillus performed noticeably better than the CV.

Couldn't get a hardness value on the Camillus because it was a two spring stockman. The blade tangs of two spring stockman blades have to be annealed so they can be crinked to fit. The tang is the only part of those blades with the proper configuration to get a hardness reading. When I have measured the hardnesses of blade tangs that I know were annealed, the measurement was in the low 40's.

Frank, sorry 'bout the "Sir," it's a southern thing, sign of respect...hard habit to break. even end up calling folks younger than me it now....just cause it was literally beaten into my head. growing up it was Sir or Ma'am or you got a smack upside your head.

on topic...thank you for the follow up. good information and details. greatly appreciated!

 

[Woods Creeper]

OFFTOPIC
Called a guy "SIR" on Sat. after , thanking him for holding a door...
he asked me not to call him "SIR"
told him , sorry I was raised to show respect...
on topic ... been handling knives and Case knives for decades now ... Case's CV steel is not the same as the carbon blades of the 60's and 70's .
Might be my imagination ... but what I believe .

 

[Obsessed with Edges]

I also don't believe the '60s - '70s blades are the same as more current ones. No idea if the steel's composition is same/different, but there has been some discussion lately, from members with means to test hardness, the older ones are frequently at much lower RC (sometimes in the 40s). I have a 1965 vintage 6265 SAB Folding Hunter that would seem to suggest that. It seems very 'soft' on the hones, compared to a more recent CV knife I've sharpened.

Having said that, I also believe there might be some 'better ones' out there, in older vintages. I've been messing around with a 1970 5220 Peanut in carbon steel, and the edges on it's two blades seem quite tough & resilient. The clip blade has a little ding from impacting the backspring on closure, and I've been impressed at how much work it's taking to smooth the ding out of that edge. Seems much less 'soft' on my hone. I can't help but think there was probably more variability in the hardness of older blades. Tolerances in general have gotten tighter with advancing technology and experience, so more modern blades probably wouldn't see as much variation, aside from the usual statistical 'anomalies' that occasionally pop up.