Risking being thrown out

mendezj

mendezj

Joined
Nov 24, 1998
Messages
993
I’m new to CPK knives yet I own and have used many, many knives, knives made by many of the better known knife makers and also good production knives; however, presently I wouldn’t go to the field without one of my two CPK knives (DEK1, FK2). I haven’t found a knife I liked so much in decades.

That said, for a hunting and fishing knife I’d also need a finer blade (not as thick from spine to edge). Again, I know I’m becoming obnoxious repeating the same thing, but I believe a knife similar to the CPK Skinner I’ve only seen in pictures, would be fantastic. The broad blade (from spine to edge) such as the DEK1 blade is great for many applications, but when shooting for birds a finer blade would be easier to use.

I just went thru most of the DEK1 thread and I’m amazed at the care and time it took to get that knife made and in the hands of users. Admirable. Congratulations. So I know it’s not easy to just make a new knife (especially considering the Amazon project). But please consider making a smaller knife for us bird shooters. Please. Thank you so much.
 
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You know, a CPK Bird & Trout would be a pretty stellar knife - not only would it be a great little EDC but it could serve wonderfully in a lot of the capacities that require a narrower nimble blade. That said, I do wonder how such a thing might jive with CPK's typical design ethos - I'm curious what Nathan and crew might have to say, maybe it's already on the radar.
 
Pàdruig said:
You know, a CPK Bird & Trout would be a pretty stellar knife - not only would it be a great little EDC but it could serve wonderfully in a lot of the capacities that require a narrower nimble blade. That said, I do wonder how such a thing might jive with CPK's typical design ethos - I'm curious what Nathan and crew might have to say, maybe it's already on the radar.
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I agree. A little bird & trout or thin skinning blade would be awesome!
 
I don’t think it’s out of the question, I’m sure it’s an application that can be addressed, but I know there is a lot on the go and perhaps asking what’s on the white board for when will help establish a time frame.

Before you found CPK, they went though a phase of choppers. Many, many models. Then choppers were done. Swords got put on the board but so did small daggers and the DEK. If the Amazon batch is next and the trend to smaller continues, perhaps we just need 1-2 projects out of the way and there will be room for another project.
 
I agree and have said in a few threads I would love a CPK B&T knife. I carry an EDC2 nearly everyday and a good B&T might well get carried more ... and it would surely see more carry through fall and bird season without question. I know there are several things in line on the white board and I will patiently await a smaller B&T knife (hopefully) in the future!
 
I hear you guys.

I am throwing a few hundred pounds of CPM Cruwear into the next run for heat treat development here over the winter. It's time to dust off my old heat treat development tools. it is a close cousin of 3V but with a little more carbon in it. As much as I like Delta 3V I think that Delta Cruwear might be even better for some of these thin knives like you guys are talking about. Let's see what we come up with over the winter.
 
Nathan the Machinist said:
I hear you guys.

I am throwing a few hundred pounds of CPM Cruwear into the next run for heat treat development here over the winter. It's time to dust off my old heat treat development tools. it is a close cousin of 3V but with a little more carbon in it. As much as I like Delta 3V I think that Delta Cruwear might be even better for some of these thin knives like you guys are talking about. Let's see what we come up with over the winter.
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Cuwear is one of my favorite steels I am really glad to hear this and look forward to what you do with it!
 
Nathan the Machinist said:
I hear you guys.

I am throwing a few hundred pounds of CPM Cruwear into the next run for heat treat development here over the winter. It's time to dust off my old heat treat development tools. it is a close cousin of 3V but with a little more carbon in it. As much as I like Delta 3V I think that Delta Cruwear might be even better for some of these thin knives like you guys are talking about. Let's see what we come up with over the winter.
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Whoa, we posted at the same time. Thank you so much for the prompt and kind response. I’ve read your writings on dressing deer and so on, and you most definitely know what you’re talking about. That is, you’ve been there, done that. And not many knife makers have the type of experience to fully understand what the user is after. If you add to that an extensive knowledge and understanding of heat treating steel and edge and bevel design, you have some amazing knife. I’ll stay tuned. Again, thank you so much.
 
Nathan the Machinist said:
I hear you guys.

I am throwing a few hundred pounds of CPM Cruwear into the next run for heat treat development here over the winter. It's time to dust off my old heat treat development tools. it is a close cousin of 3V but with a little more carbon in it. As much as I like Delta 3V I think that Delta Cruwear might be even better for some of these thin knives like you guys are talking about. Let's see what we come up with over the winter.
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You know it goes without saying, I’ll take one and maybe a thinner one if you are up to grinding it.;):)
 
tinfoil hat timmy said:
What's cruwear?
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It is the parent steel that 3V was originally derived from. The particle metallurgy version (the CPM version) has a finer carbide distribution than the original wrought (duh) but it unexpectedly developed slightly different carbide chemistry as a result of the manufacturing process with some positive attributes. Compared to 3V it has the same amount of Chrome and a similar amount of vanadium (less on paper but about the same in practice) but there is a little more moly (which was probably added to improve hot hardness, but we're interested in the toughness and pitting resistance) and a significant amount of added tungsten with a related increase in carbon to form tungsten carbide in the steel. Who doesn't love some tungsten carbide? Cruwear is still a moderate carbide volume fraction and is designed to run a little harder than 3V. It could have fantastic edge stability potential and good toughness given the right tweaks.

3V is intended to be a lath martensite (one reason it's so tough) but in addition to our tweaks to address retained austenite without resorting to the secondary hardening hump we're also putting enough carbon into solution to start forming some plate martensite. This is one of the things we did to enhance edge stability, but a side effect of this tweak was an increase in tendency to stabilize RA which required other tweaks otherwise it has the opposite of the intended effect (RA = mushy edge). The entire Delta protocol was a complex interaction of these variables and changes to both the manufacturing process of the steel itself (ours is spheroidized differently) and the heat treating process that required changes at Peter's to duplicate. Cruwear, on the other hand, was designed to form plate martensite from the start.

Based on our optimization of 4V and V4E and D2 I believe that Cruwear has potential, but the specific interactions between the variables will be different and there could be some igotcha in there that makes it a non-starter, but my hope is a higher carbon steel with similar design as 3V will work better than 3V at the higher hardness I'd like to use for some smaller knives. 4V (V4E) had some very good properties and we're winning almost every cutting competition we enter with it at harnesses over HRC 63, but it lacks the corrosion resistance needed for a broad appeal. I'm hoping that CPM Cruwear can be my go-to steel for higher hardness applications. It's a little more moderate than 4V, it shines at HRC 62, and the rust resistance will be pretty decent in an optimized version due to the additional free chromium (if we can keep that carbon tied up in all that vanadium and tungsten, there is plenty of chrome for the job). This free chrome is a happy side effect of the quench rate and tempering temperatures used in our tweaks to improve edge stability. It has worked in other steels we've used and I expect it will work here too.
 
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Nathan the Machinist said:
It is the parent steel that 3V was originally derived from. The particle metallurgy version (the CPM version) has a finer carbide distribution than the original wrought (duh) but it unexpectedly developed slightly different carbide chemistry as a result of the manufacturing process with some positive attributes. Compared to 3V it has the same amount of Chrome and a similar amount of vanadium (less on paper but about the same in practice) but there is a little more moly (which was probably added to improve hot hardness, but we're interested in the toughness and pitting resistance) and a significant amount of added tungsten with a related increase in carbon to form tungsten carbide in the steel. Who doesn't love some tungsten carbide? Cruwear is still a moderate carbide volume fraction and is designed to run a little harder than 3V. It could have fantastic edge stability potential and good toughness given the right tweaks.

3V is intended to be a lath martensite (one reason it's so tough) but in addition to our tweaks to address retained austenite without resorting to the secondary hardening hump we're also putting enough carbon into solution to start forming some plate martensite. This is one of the things we did to enhance edge stability, but a side effect of this tweak was an increase in tendency to stabilize RA which required other tweaks otherwise it has the opposite of the intended effect (RA = mushy edge). The entire Delta protocol was a complex interaction of these variables and changes to both the manufacturing process of the steel itself (ours is spheroidized differently) and the heat treating process that required changes at Peter's to duplicate. Cruwear, on the other hand, was designed to form plate martensite from the start.

Based on our optimization of 4V and V4E and D2 I believe that Cruwear has potential, but the specific interactions between the variables will be different and there could be some igotcha in there that makes it a non-starter, but my hope is a higher carbon steel with similar design as 3V will work better than 3V at the higher hardness I'd like to use for some smaller knives. 4V (V4E) had some very good properties and we're winning almost every cutting competition we enter with it at harnesses over HRC 63, but it lacks the corrosion resistance needed for a broad appeal. I'm hoping that CPM Cruwear can be my go-to steel for higher hardness applications. It's a little more moderate than 4V, it shines at HRC 62, and the rust resistance will be pretty decent in an optimized version due to the additional free chromium (if we can keep that carbon tied up in all that vanadium and tungsten, there is plenty of chrome for the job). This free chrome is a happy side effect of the quench rate and tempering temperatures used in our tweaks to improve edge stability. It has worked in other steels we've used and I expect it will work here too.
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This will come across as a very dull (pun intended) comment. However, as I read your very interesting response I sensed that the thought process initiated at the hand. That is, from the experience of working with a knife in your hand to applying your knowledge of metallurgy to improve your experience with the knife, and not the other way around. This sounds lame to the max but I think it’s very important. I don’t know the first thing about steels but I’ve used knives for more years than I’d like to acknowledge and I’ve often found myself thinking about how the steel on my knife could better perform. And I believe the CPK approach is what makes these knives superior.
 
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