Case Carbon Steel

They make their living on tradition, not innovation. If the steel is the same, I guess it must be the heat-treatment that has changed, because I can tell the difference between sixties Case carbon steel and modern CV blindfolded, just by the feel on a whetstone.
 
yablanowitz said:
They make their living on tradition, not innovation. If the steel is the same, I guess it must be the heat-treatment that has changed, because I can tell the difference between sixties Case carbon steel and modern CV blindfolded, just by the feel on a whetstone.
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What is the difference?

Could you explain more?

thanks
 
db said:
Personally I'd be a little shocked to read that the steel used today is the same they used from the beginning. I'm pretty sure I wouldn't think that was a good thing.
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I am surprised too.
But I don't have a problem with Case using ol' fashioned steels. They say they have updated the heat treat process over time. Simple steel with proven HT is all I need. Some companies can really make great blades out of steels that are often looked down on; Case and Buck are two great examples.
 
Hi,

I too would be very surprised if the steel was the same from the beginning. If I remember my machinist's history, (I hope I'm not too old to remember long ago classes :confused:), chrome vanadium steels wouldn't have been a recognizable alloy, in and of itself, until around WW1, (give or take a few years). Though it would have been found as trace impurities. And again during WW2 CV type steels would have been considered "strategic" material and been allocated to the war effort and not pocket knives. Today saying chrome vanadium steel, can cover a pretty wide spectrum of uses. From knife blades to wrenches to bearing races. So Case's secret is pretty safe.

I would believe that after WW2 Case CV could be the same. And their Tru-Sharp stainless could also be the same. Though if push comes to shove, I'd guess Case's Tru-Sharp maybe more apt to change than their CV. And if you toss in the fact the record keeping may not have been totally up to snuff back in the day, or may have been lost or destroyed. Then it is very possible no one can say that it was ever different.

In any case, either steel makes a pretty good blade for a slip-joint for my use.

dalee
 
neeman said:
What is the difference?

Could you explain more?

thanks
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It's hard to explain, but when I'm sharpening, I do it as much by feel and sound as I do by eye. The sound changes when the edge gets to the stone, both the resistence and sound change if the bevel is not flat on the stone, etc. To me, the modern CV feels softer than the carbon steel from the sixties and back. It seems to abrade more easily than the old steel. It feels less slick when it slides across the stone. Something like that. Like I said, hard to explain, but I can sure feel it.
 
yablanowitz said:
It's hard to explain, but when I'm sharpening, I do it as much by feel and sound as I do by eye. The sound changes when the edge gets to the stone, both the resistence and sound change if the bevel is not flat on the stone, etc. To me, the modern CV feels softer than the carbon steel from the sixties and back. It seems to abrade more easily than the old steel. It feels less slick when it slides across the stone. Something like that. Like I said, hard to explain, but I can sure feel it.
Click to expand...

That sounds like a heat treatment issue.
 
I don't know if you can call it an "issue" when it is consistent over the half dozen of each type (old and new) that I have. More likely just a change of heat-treatment.
 
Blues said:
On a related note, (and purely out of curiosity):

When did Case begin marking their blades as CV and was that indicative of a change of the steel's formula? (As in a change from 1095 or similar to an alloy with added chromium and vanadium.)


EDITED TO ADD;

I had a long conversation with a very nice gentleman at Case this morning and hope to have some further information to post on this subject.
His thought, however, was that the steel composition had not changed though the art of the heat treat itself had been refined over the years. (He also shared that they have been using the same ovens for heat treating the blades for many, many years.)

An interesting aside that he shared was that in some independent tests they had run for them, their stainless steel actually outperformed the CV. (Hey, I'm just sayin'. Don't shoot the messenger. :p)
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You got my curiosity going with that last part. So I paid Kenny's web site a visit and he sent me a CV blade and a True Sharp blade. (Sodbuster and mini-trapper, respectively.) Kenny has the fastest satisfaction time on the internet. I ordered Way Way late on Wed night. Got them today, Saturday. From OK to CA in 3 days. That's Fast.

I sharpened each to a 15° angle on the Sharpmaker and cut 3/8" manila rope. 10 cuts each. After the cuts, I looked at each edge under a hand lens for damage. I repeated the procedure 3 times. The CV showed less deformation (dulling) than the True Sharp. (But a Buck 301 was better than the CV.)

I suppose the results depend on the test method. But this is the one I use. That's what I did and that's what I saw.

Don't shoot me either. :o

NOTE: Those yellow Cases sure are well built. I may have to get me some more.
Rats, more knives to go on my wish list. Frickin list keeps getting longer no matter how many knives I buy. Worse than peanuts (the eating kind).
 
knarfeng, I think that your test would have more "validity" if both blades had the same profile and geometry (as in two sodbusters or two mini-trappers) and not just the same final edge angle. Nonetheless it's always good to hear various data points.

Unfortunately, I don't think I'll be able to get more info in regard to the above as it starts getting into "proprietary information" area and I don't want to burn any bridges with the folks I've had the good fortune to develop a rapport with over at Case.
 
I believe that profile has little effect when cutting rope. The cut rope pulls away from the blade, so only the edge makes contact.

Sorry for the post as its subject matter is a bit out of bounds here, I know. Once I measure the blade hardnesses, I'll write it up and post it in the testing forum, likely next weekend. Just thought I'd post a quickie here cause we were talking about CV vs. True Sharp.

Understand about not being able to post further info from Case. I was hopeful, but doubtful of you being allowed to post Case secret info.

Thanks,
Frank
 
A Rockwell hardness test of CV versus True Sharp is something that everyone has been wanting to see for years. Very interesting, and I will be watching your posts. :thumbup:
 
Frank, thanks for sharing your tests and their results.

Out of curiosity, where on the blades did you check the hardness?
 
The hardness test requires a flat sample. The only flat place on these was at the base of the blade as it comes out of the handle.
 
Thanks again, Frank. I figured it to be in that general area just wanted to get a mental picture.
 
knifeaholic said:
Case anneals their blade tangs to soften that area so not sure that is a representative hardness.
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Thanks knifeaholic. Softer tangs even softer than back springs has been my experience with spring back knives, as tang back wear is the most often cause of weak blade action or so called Walk and Talk on older knives. New knives with weak blade action is usually caused by weak back springs...
 
knifeaholic said:
Case anneals their blade tangs to soften that area so not sure that is a representative hardness.
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1) That mini-trapper blade is a pretty small chunk of steel. It is not clear to me that it is possible to anneal the tang of a small blade like that of the mini-trapper without affecting the hardness of the entire blade. I don't see differential heat treating on a mass production scale as a viable process for a blade this size.

2) AG Russel lists the hardness of Case Tru-Sharp at 54-57, so I do not feel my measurement of 55 should be unexpected.

3) When I did my edge retention comparison between Tru-Sharp and CV, I also tested a Buck 301 in 420HC. The Buck 301 had a measured blade hardness of 59.7, also measured at the tang. The Buck greatly out-performed both the CV and the Tru-Sharp steel in manila rope cutting edge retention tests. (See referenced thread above for the measurement technique.) I take this as another indication that my hardness measurements are reasonable answers.

Frank
 
knarfeng said:
1) That mini-trapper blade is a pretty small chunk of steel. It is not clear to me that it is possible to anneal the tang of a small blade like that of the mini-trapper without affecting the hardness of the entire blade. I don't see differential heat treating on a mass production scale as a viable process for a blade this size.

Well, I was in the Case factory this week for a tour and I saw them doing it with an induction annealing machine. I do not know just how far up into the tang the annealing process affects.

2) AG Russel lists the hardness of Case Tru-Sharp at 54-57, so I do not feel my measurement of 55 should be unexpected.

3) When I did my edge retention comparison between Tru-Sharp and CV, I also tested a Buck 301 in 420HC. The Buck 301 had a measured blade hardness of 59.7, also measured at the tang. The Buck greatly out-performed both the CV and the Tru-Sharp steel in manila rope cutting edge retention tests. (See referenced thread above for the measurement technique.) I take this as another indication that my hardness measurements are reasonable answers.

Frank
Click to expand...


see my comment above
 
Holy crap, thats a high reading for 420HC. Of course, it also explains a lot of good things I've heard about it. I'm really gonna have to send my Scout Lite back for a new blade if they get it that hard.
 
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