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SOLD, 40, Basic 5" Field Knife, Optimized CPM Cruwear

Nathan the Machinist said:
Please be aware that these knives were produced as heat treat development mules for us to evaluate and optimize CPM Cruwear. They were run at the same time we ran our production run in 3V. These were never intended to see the light of day. They're rough with visible tool and grind marks. These are not our signature series, they were made to be used, abused and evaluated. These are the left overs from that process. We consumed every single test mule developing our heat treat for Magnacut and even had to dip into the production run to complete our work. That was not the case with the Cruwear because it is closely related to CPM 3V and we have a lot of experience working with materials in this family. So these are leftovers. They're rough. Some are very light stamped. Don't buy these looking for a beauty queen. These are rough work knives with a high performance heat treat.

Here is a photo demonstrating some of the development work that went into Cruwear. I like this picture because it perfectly captures what we're trying to accomplish with our low temp tweak and what it looks like when it works and what can go wrong.

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All three blades are a similar hardness and are sharpened at 18 DPS. We use a narrower angle when doing development work because it makes issues with edge stability more obvious.

These blades, and the other test blades, all made practically identical cuts in the same test mediums including well seasoned deck planking, osage orange and finally driven through 16 penny carpenters' nails (big nail used in construction for framing etc.) multiple times. We look at things like wear and edge loss/damage from sliding whittling cuts, pryout cuts and chopping etc. One important fact that I really want to drive home to folks is that the use of the secondary hardening hump (the industry standard heat treat) improves wear resistance at the expense of edge stability and ultimately results in less edge retention. Wear resistance is not the same thing as edge retention. The two terms are often used interchangeably in this industry and that is a mistake. Unless you're using your knife in light and tightly controlled cuts in soft abrasive media such as gritty paper you will not see any benefit from the precipitation of additional secondary carbide. You're better served keeping that carbon in the martensite where it can better support the primary carbide and the fine cutting edge.

In that picture all three blades were driven through 16 D nails. The blade on the bottom is a control sample given the industry standard heat treat and displays the mushy crumbly edge typical of the high temp secondary hardening hump. The blade on the top is a failed low temp tweak, in this case I believe it has excessive stabilized retained austenite. That is a huge pitfall when utilizing a low temp tweak. These steels often need that high temp to decompose retained austenite and every steel has different needs and a different approach. This steel is more like D2 than 3V in this respect. However I have perfected this process in both of those materials and I achieved the results that you see in the middle test piece.

My heat treat is special. There are aspects of it that are not obvious. Scanning electron microscopy of my Delta 3V has shown structures at a nanoscopic scale that substantiates to me that our tweaks (which were developed empirically through a process of trial and error and tightly controlled test and evaluation processes) are legitimately different and better. I have not had my Cruwear evaluated in this way but I suspect a similar mechanism is at work here too.

We make durable knives. The design, geometry and steels we select are tough. But tough steels are not always durable. For example, low hardness 4130 steel is very tough, but the edge stability is poor and it will quickly come apart at the edge in rough use. 3V is inherently tough, but we made it durable by addressing it's biggest weakness, mediocre fine edge stability. What good is a tough abrasion resistant steel if it goes dull from edge loss in impacts. We fixed that. Our knives are all about edge retention in a durable knife. That has always been the case. We're pursuing performance, which is multi faceted.

By the way, if you'll permit me to make a big flex here, I would like to boast about our pursuit of performance through the utilization of advanced metallurgy applied to optimized design and geometry and our winning run at the Blade sports world cutting championship in Atlanta two weeks ago.

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We are the only production knife company to ever win a National and a World cutting title and we're the only people to hold both titles simultaneously in recent times. I've got to brag here folks. We're doing the work and making the best knives of their kind available anywhere. And this humble field knife is a part of that heritage.



Why use Cruwear? I can't get 3V this hard without it becoming very chippy. HRC 60.5 is pretty hard in historical context, but some of you special knife nuts want even harder steels. Our race knives are HRC 64. There are pros and cons to that, but I like Cruwear as a well balanced material at high hardness. And, like Delta 3V, an unintentional side effect of utilizing a low temp tweak is substantially improved corrosion resistance. By keeping the carbon tied up in the martensite we're not developing as much chromium carbide, which helps keep more free chrome in the matrix. The other carbides, such as vanadium and tungsten don't dissolve as much during heat treat and are largely permanent primary carbide, the chrome is disproportionately affected by this tweak. That carbide is relatively soft, not that much harder than the matrix, so you won't miss it and the enhanced edge stability and corrosion resistance more than offset it.

If you want the ultimate in a tough durable low maintenance knife, stick to our Delta 3V. It's such a fantastic material, with an almost magical ability to remain sharp in rough use and never ever fail you. But if you want a little more edge retention and wear resistance in a reasonably durable steel that still has decent corrosion resistance, you're going to like our Cruwear.



Please pardon the re-use of the original pictures. These knives in these pictures are marked 3V, but the knives for sale today will be marked CW.

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The Basic 5" Field Knife is a stout, medium sized woods knife and general purpose work knife for tradesmen and hunters. It is based on our very popular standard Field Knife, the FK2, but it has been tweaked in order to invite some tough love from you knuckleheads who don't want to beat on their standard Field Knife.

Some things have changed, some things are have stayed the same.

They are both 3/16" stock. These are CPM Cruwear at HRC 63-64 with a variation of the Delta heat treat protocol
The handles are interchangeable

The primary grind is 1/4 degree steeper (slightly more obtuse)
The edge is sharpened at 20 DPS, up from 18
The blade is 5/8" longer
The blade is not skeletonized (and is 2 ounces heavier, but the balance point is the same)
There is no hidden lanyard hole
The scales are somewhat simplified with less contouring. (It is still supremely comfortable and very well thought out)
There is no jimping on the thumb ramp
It is significantly less expensive and is begging for your rough love.

It is thick but not overly thick. It is a strong performer, it cuts well. However you can not break this knife without tools such as a big hammer or a prybar. If you can break or significantly damage this knife (without the use of tools) I will replace, repair or refund. Go nuts.


Specs:

CPM Cruwear, Delta Heat Treat protocol, 63.5 HRC, .188" thick at ricasso, sharpened 20 DPS.
Total length 10.4"
Blade length 5.5"
Weight 10.2 oz
Grippy 3D machined scales in your choice of black or natural micarta
18-8 stainless steel fasteners


Mashed Cat sheaths with semi rigid drop loop are custom made for these knives and are well designed and well made. TecLok available upon request.


These are all field grade, milled, ground and tumbled with tool and grind marks.


Also, if you would prefer a rough 100 grit hand ground (ghetto satin) finish on your bevels rather than tumble you can select this as a $40 option. If you want a rough hand ground hollow grind, that is a $100 option. I don't know why you would want that, it isn't a better option for this knife, but Mark will do it for you if you want it.


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The price in basic configuration, black or natural canvas micarta, with sheath and shipping: $308 ($295 + $13 shipping). Please limit your order to one per post. If you want multiples you will need to make multiple posts. I'm doing this to prevent folks from ordering a bunch at one time, causing us to run low on stock before other folks have an opportunity to select something they would like. Multiples do not accrue additional shipping.

Today's sale is for 40 knives.

Come back in two weeks for a few more of these.
Click to expand...

Truly an impressive breakdown of an air tight design ideology.
 
It would be amazing if these sales could be run as a lottery once in a while. Leave thread unlocked for five minutes for people to put entries in than random number generate 40 numbers corresponding to user post #. Much more fair. Ill never get in with my slow internet anymore. Congrats to the winners.
 
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