How can I tell if my knife is really CPM 3V and not A2?

L

LeatherStrop

Joined
Jun 15, 2015
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So, is there any practical way to examine the natural factory steel finish and see this or maybe by soaking the steel in vinegar and examining the resulting stain? I am curious because I saw another thread where it was determined that the person purchased a knife that was labeled CPM 3V and it was really A2.
 
No expert here but I have worked with both. Mosty A2
A2 hangs onto more of a super thin foily bur when sharpening to 8000 or so. 3V tends to be a little easier to get rid of the bur.
Not too helpful ?
OK try this. A2 will get little dots of red rust if you have it really clean (no oils, no soap etc) and rinse it under hot water and watch it dry; doesn't take long like a minute or two.
I have never seen these little red dots of rust on 3V. 3V does darken ever so slightly with use; kind of a subtle dark cast to it.
 
Wowbagger said:
No expert here but I have worked with both. Mosty A2
A2 hangs onto more of a super thin foily bur when sharpening to 8000 or so. 3V tends to be a little easier to get rid of the bur.
Not too helpful ?
OK try this. A2 will get little dots of red rust if you have it really clean (no oils, no soap etc) and rinse it under hot water and watch it dry; doesn't take long like a minute or two.
I have never seen these little red dots of rust on 3V. 3V does darken ever so slightly with use; kind of a subtle dark cast to it.
Click to expand...

Thanks that is easy to check.
 
1p71o8.jpg
 
I have several knives that came out of Mike Stewart's shops: a pair of Marble's Campcraft and a Fieldcraft in 52100 from his time there, and a Woodland in A2 when he started Bark River. All are superb examples of the knifemaker's art IMHO. I wouldn't hesitate to buy any of his knives, in any steel he chooses to use.
 
The only way to tell for sure is to have them tested for alloy content. Anything else is just guessing. Educated guessing perhaps, but just guessing none the less.
 
Hey here's an idea; send it to Jason to be sharpened. I bet he could tell in a New York minute.
 
strategy9 said:
If you can baton through a concrete curb, 3v for sure.
If not, probably a2.

*sorry, couldn't resist.
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This ^^^

Hey aaaaaaaahhhhhh
HEADS UP . . . do not let the blade SIT in water. That is not what I said or meant.
Again RINSE the blade in hot running water under the tap and then WATCH IT DRY.
The rust shows up as and just after the blade is dry. Wiping it dry will wipe away the rust.
Hot, hot water so it will evaporate fast while you watch.

And again, and this is subtle and important :
THE ONLY RUST YOU ARE GOING TO SEE ARE MINUSCULE PIN PRICK SIZE DOTS.
This is for A2.
PS: you probably are going to want to get some magnification on the A2 just to be able to see the rust dots. Really subtle.
 
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My wife threw my gunny A2 in a sink full of soapy water over night, some staining slight surface rust that wiped right off. A2 takes a keen edge. I wouldn't sweat it. Use that thing.........
 
A2 takes a keen edge. I wouldn't sweat it.

You pay for 3V you expect 3V performance . . . and get A2 . . . THAT is a problem.
A keen edge can be had on a butter knife.
3V is a demolitions tool.
A2 is a pretty good all around cutting tool.
 
Deer processing or masonry (destruction :D :thumbsup:) 3V seems to have it going on.


PS: I’m all for thinning those suckers out though
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A2 stains very easily. I patinead A2 with mustard in about 30 minutes. 3V had no reaction to mustard.

Take a papertowel and dab some mistard on an area that you can easily buff later to remove the patina. Make sure its a super thin layer so oxygen can react with the mustard. It will gove you a bluish gray patina. I tried to force a patina on 3V and it wouldnt take one.
 
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I agree with either the rust or patina method. I have knives in both steels. A2 will develop a patina quickly. None of my knives in 3V have developed a patina in spite of a lot of use.
 
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