Field knife steel choice.

Which would you prefer?

  • CPM 154

    Votes: 0 0.0%

  • S35VN

    Votes: 0 0.0%

  • CTS-XHP

    Votes: 0 0.0%

  • CPM 3V

    Votes: 0 0.0%
  • Total voters
    0
jimnolimit said:
there is nothing wrong with 1095 or 1095 Cro-Van, they're good steels but those steels aren't going to outperform CPM-3V especially with a custom heat treat.
Click to expand...

LIES!! My BK7 will slice through a BUS made of CPM-3v in a flurry of glowing steel and screaming school children!

or is that my Lightsaber? I get those two confused sometimes... which one did Ethan design?
 
And a few others if I can find them. I would like to find a place that does 2-3 stage salt bath austenizing with multiple options for quench method/medium (oil or low temp salt out of austenizing, water quench out of first temper) does cryo, can temper in salt and will take small orders. Not every demanding, am I? LOL.
jimnolimit said:
i would contact both peters and paul bos heat treating and ask.
Click to expand...
 
jdm61 said:
And a few others if I can find them. I would like to find a place that does 2-3 stage salt bath austenizing with multiple options for quench method/medium (oil or low temp salt out of austenizing, water quench out of first temper) does cryo, can temper in salt and will take small orders. Not every demanding, am I? LOL.
Click to expand...

perters and/or paul bos should be able to handle your order, call and ask.

another option is to contact a few of the makers on here that do there own heat treating (like phil wilson or farid for example). some of these makers might have devised their own heat treat regimen to squeeze the most performance out of 3V. you could ask in the makers section.
 
Most send it out or use an oven, which I have. Farid lives in the UK. if I was going to do that, i would ship it to my buddy in Belgium who does HT for FN Herstal and the Belgium gummint.;)
jimnolimit said:
perters and/or paul bos should be able to handle your order, call and ask.

another option is to contact a few of the makers on here that do there own heat treating (like phil wilson or farid for example). some of these makers might have devised their own heat treat regimen to squeeze the most performance out of 3V. you could ask in the makers section.
Click to expand...
 
jdm61 said:
Most send it out or use an oven, which I have. Farid lives in the UK. if I was going to do that, i would ship it to my buddy in Belgium who does HT for FN Herstal and the Belgium gummint.;)
Click to expand...

i was just using them as an example.

a quick google search for salt bath heat treating turned up a bunch of companies, i see many phone calls in your future ;)

p.s. when you do this project, i hope you make a full thread on it.
 
Yeah. I e-mailed one that said they had everything I needed but got no answer, so i will have to call.
jimnolimit said:
i was just using them as an example.

a quick google search for salt bath heat treating turned up a bunch of companies, i see many phone calls in your future ;)

p.s. when you do this project, i hope you make a full thread on it.
Click to expand...
 
Salts for 3V, why? And what is your intended hardness? Anything above 60 and my personal preference would be CPM-M4 or Vanadis 4E/CPM-4V for the extra wear resistance at the same toughness.
 
Salt for slightly more hardness with no loss of toughness, small ausgrain because you don't have to heat it for as long and it spends one to two cycles below austenizing temperature, less chance of warping, more even heating, faster quench so higher hardness, etc, etc. Cryo to reduce RA and also so that it can be tempered at the lower temperatures instead of at 1000F. Water quench after first lower heat temper to fix RA and reduce embrittlement, second temper to convert the rest of the RA, etc, etc. If you are going to drop $30-50 for a piece of raw steel, why leave ANY performance on the table? Even the Crucible generic spec sheet says that salt will give you the maximum attainable toughness for a specify heat treat regimen. That says maybe you can go up to 62 without as much loss of toughness as you get with straight air hardening at 62. With that said, I am anxious to see how the 4V works. M4 does not have anything close to the impact resistance/toughness that 3V does. It actually has less impact resistance that good old A2. Plus, it is supposed to be a cast iron bitch to finish. LOL
hardheart said:
Salts for 3V, why? And what is your intended hardness? Anything above 60 and my personal preference would be CPM-M4 or Vanadis 4E/CPM-4V for the extra wear resistance at the same toughness.
Click to expand...
 
Last edited:
Now if people are looking for price, I could always opt for going down the road to the junkyard and picking up some old Jeep leaf springs and wrapping the tang in Gorilla Glue soaked bailing twine.:D
 
jdm61 said:
M4 does not have anything close to the impact resistance/toughness that 3V does. It actually has less impact resistance that good old A2. Plus, it is supposed to be a cast iron bitch to finish. LOL
Click to expand...
It does get much closer if you go over 62 on the 3V or underharden the M4. Would be closer if they didn't switch over fully to the HC form of CPM-M4. The big thing is that you get around twice the wear resistance for losing about one fifth the impact resistance at 62. A2 doesn't even figure into the equation when wear is considered. Just depends on what you're looking for. Got my 3V knives at 58 and 60, where impact toughness is still pretty good, so the low wear resistance is better balanced.
 
True, but the impression that I get is that with the crazy salt method, you could go to at least 59 and 61 or maybe even 59.5 or 61.5 without any real loss of impact resistance. Roman Landes has a pretty strong opinion that NO suitable knife steel should be left any softer than 60 for normal knife applications. He used the technique that I posted on plain old ATS 34 for his doctoral dissertation and was able to get very good results even with that pedestrian old stainless steel. He said that the difference is that 20 or even 30% retained austenite may be "just fine" for some folks for typical tooling applications where time and cost is an issue, but it is not good for knives, so controlling the aus-grain size of the matrix is critical so you can get that ability to have a very fine, yet strong and stable edge.
My exposure to M4 has been from the guys who use it for the cutting comp knives. Gayle Bradley was joking about it and yet not joking when he told me that you shouldn't really think about doing anything other than a machine finish once you harden the stuff.
hardheart said:
It does get much closer if you go over 62 on the 3V or underharden the M4. Would be closer if they didn't switch over fully to the HC form of CPM-M4. The big thing is that you get around twice the wear resistance for losing about one fifth the impact resistance at 62. A2 doesn't even figure into the equation when wear is considered. Just depends on what you're looking for. Got my 3V knives at 58 and 60, where impact toughness is still pretty good, so the low wear resistance is better balanced.
Click to expand...
 
True, but the impression that I get is that with the crazy salt method, you could go to at least 59 and 61 or maybe even 59.5 or 61.5 without any real loss of impact resistance. Roman Landes has a pretty strong opinion that NO suitable knife steel should be left any softer than 60 for normal knife applications. He used the technique that I posted on plain old ATS 34 for his doctoral dissertation and was able to get very good results even with that pedestrian old stainless steel. He said that the difference is that 20 or even 30% retained austenite may be "just fine" for some folks for typical tooling applications, but it is not good for knives, so controlling the aus-grain size of the matrix is critical so you can get that ability to have a very fine, yet strong and stable edge. One of the things that concerns me about the high tempering temperatures that you see on the Crucible spec sheets is that some folks have told me that the steel is VERY sensitive to even the slights percentage change in temperature when you get up to say 1000. 25 degrees at low temp on something like CTS-XHP is not going to do much of anything drastic until you get up to like 450-500 from what I read on the Carpenter speed sheets, but people tell me that it can make quite a difference with 3V at the higher temps. With that said, Roman said that the higher temps are an absolute must of you don't have cryo. Otherwise you are going to have a LOT of RA.
My exposure to M4 has been from the guys who use it for the cutting comp knives. Gayle Bradley was joking about it and yet not joking when he told me that you shouldn't really think about doing anything other than a machine finish once you harden the stuff.
hardheart said:
It does get much closer if you go over 62 on the 3V or underharden the M4. Would be closer if they didn't switch over fully to the HC form of CPM-M4. The big thing is that you get around twice the wear resistance for losing about one fifth the impact resistance at 62. A2 doesn't even figure into the equation when wear is considered. Just depends on what you're looking for. Got my 3V knives at 58 and 60, where impact toughness is still pretty good, so the low wear resistance is better balanced.
Click to expand...
 
jdm61 said:
True, but the impression that I get is that with the crazy salt method, you could go to at least 59 and 61 or maybe even 59.5 or 61.5 without any real loss of impact resistance. Roman Landes has a pretty strong opinion that NO suitable knife steel should be left any softer than 60 for normal knife applications. He used the technique that I posted on plain old ATS 34 for his doctoral dissertation and was able to get very good results even with that pedestrian old stainless steel. He said that the difference is that 20 or even 30% retained austenite may be "just fine" for some folks for typical tooling applications where time and cost is an issue, but it is not good for knives, so controlling the aus-grain size of the matrix is critical so you can get that ability to have a very fine, yet strong and stable edge.
My exposure to M4 has been from the guys who use it for the cutting comp knives. Gayle Bradley was joking about it and yet not joking when he told me that you shouldn't really think about doing anything other than a machine finish once you harden the stuff.
Click to expand...

but would the same be true if you did the crazy salt method for CPM-M4? maybe you could get CPM-M4 to retain more toughness at 62-63HRC.
 
Sure, but you get to a point where you run into how much toughness the chemistry will give you and that will always be higher with something like 3V, S7 or L6 because that is what they are made for. Also, the thought of trying to grind finish and sharpen hardened M4 at higher hardness levels scares me. LOL
jimnolimit said:
but would the same be true if you did the crazy salt method for CPM-M4? maybe you could get CPM-M4 to retain more toughness at 62-63HRC.
Click to expand...
 
jdm61 said:
Sure, but you get to a point where you run into how much toughness the chemistry will give you and that will always be higher with something like 3V, S7 or L6 because that is what they are made for. Also, the thought of trying to grind finish and sharpen hardened M4 at higher hardness levels scares me. LOL
Click to expand...

i'm no expert, but here is my thinking/idea:

3V's overall performance is pretty much maxed out at 60HRC. if you can get it to 60.5 or maybe even 61HRC and maintain most of it's toughness, great, but it's wear resistance will be about the same (about half that of CPM-M4). most of the toughness charts i have seen for CPM-M4 are at 62HRC. if you can get CPM-M4 to maintain the toughness it would have at 60-61 while it's hardened to 62-63, i think that would be better.

as far as sharpening and finishing hardened CPM-M4, silicon carbide, boron carbide and diamond are your best friends ;)
 
Last edited:
You must log in or register to reply here.
Back
Top