Survival knife ?

Having now seen the actual, or close to it, I'm lovin' it. I need at least one and another, if it's in the cards. After that, I'll become a trading hoarder, lol - or was that a hoaring trader?

I predict this model will overwhelm!
 
Nathan the Machinist said:
We've been kinda holding off on sneak peaks as we try to dial in the details, but these are the three machined prototypes where we're evaluating different edge thickness on functional models in Delta 3V.

1_6.jpg~original


11.8" total length, 6.5" blade.

We're still dialing in the handle, choil geometry and some small details but we hope to be close enough to go ahead and order a custom run of 3V in a special gauge for this project.
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DROOL !!!!!! Nice 👍
 
Yep. Nathan, you made exactly what I was hoping for. I didn't know what I wanted it to look like until I saw that picture. Looks like I can sell any other knife I own larger than the FK besides my LC.
 
ndmiller said:
Looks great, is the rainbow fuller an Optical illusion or a byproduct of heat treat or ?
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I believe it is from the heat treat. I am not sure but I don't think it should have all those colours, maybe Nathan can drop some knowledge on the subject
 
Revolverrodger said:
Could it be oxydes from the HT ?
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Yes, the blade passes through the temperatures where those particular oxides form pretty quickly and any stray bit of oxygen reacts to form a colorful oxide film in places. It was on the bevels too but those areas were subsequently ground. It's usually unpredictable what it will look like on any particular blade, but it is almost always present unless the blade is heat treated in a vacuum furnace.
 
Hi Nathan,

If I may ask, the survival knife pictured here. Is that the final process before the stonewash step ? Guess I'm asking what does the 3v look like before stonewash ? I like the way it looks in the pic with the machining marks :):)
Great blade !!!!
Thanks
 
Nathan the Machinist said:
We've been kinda holding off on sneak peaks as we try to dial in the details, but these are the three machined prototypes where we're evaluating different edge thickness on functional models in Delta 3V.

1_6.jpg~original


11.8" total length, 6.5" blade.

We're still dialing in the handle, choil geometry and some small details but we hope to be close enough to go ahead and order a custom run of 3V in a special gauge for this project.
Click to expand...

Ohhhh damn!! !!! This looks great!!!
Can't wait!!
 
This is pretty much THE knife I have been looking for for a long time
Well done Nathan and Lorien

If by any chance you are looking for a beta tester to give it a serious workout I would be delighted to help
 
Needless to say that this pattern will be EPIC and I would wager that if Nathan / Jo do an initial public offering of say 100 units, those will sell in record time under 5 minutes and the only reason it would even take 300 seconds would be because that sales thread will cause a massive Internet lag time on here because of sheer demand!!!

I sincerely hope that Nathan can come up with a parallel plan in addition to the Fridays Sale to cater to the monster demand the "survival knife" has already generated. I may even fly out to the Carothers to charm my way into getting one of these off their shelves and while at it, cast a stink eye on whatever ColiledWire is going to be getting in future because he's been a bit of a brat to me lately :p
 
I'd also really appreciate it if a pre-order was done at some point :D
 
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Nathan the Machinist said:
Yes, the blade passes through the temperatures where those particular oxides form pretty quickly and any stray bit of oxygen reacts to form a colorful oxide film in places.
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So the heat brings the "pretty" colors out, but why do they form? What do those "pretty" colors indicate from a metallurgical perspective? Might one be able to use those colors in a Stress–strain analysis of the metal? And if so, what do they mean from that perspective? Especially those two main pretty BLUE HAZ? (Heat Affected Zones) I would like to learn, please advise. :D
 
Coke said:
So the heat brings the "pretty" colors out, but why do they form? What do those "pretty" colors indicate from a metallurgical perspective? Might one be able to use those colors in a Stress–strain analysis of the metal? And if so, what do they mean from that perspective? Especially those two main pretty BLUE HAZ? (Heat Affected Zones) I would like to learn, please advise. :D
Click to expand...

This is a color chart that gives an idea what oxide colors mean on steel:

aa26ff754633c9b9f886ef2c354f4f9c.png


The color of a oxide film would have no effect on a stress strain relationship, which is simply a straight line on a linear elastic material like steel until the yield point, which is a function of the strength and hardness, and nothing to do with a thin oxide film.

A blue color sometimes indicates a heat of around 500-600F, but in this context it doesn't mean much of anything because the blade goes many times hotter than that during heat treat. Blades that are heat treated in a sealed low oxygen environment pick up random heat colors. There isn't much meaning to attribute to it. From a metallurgical perspective they don't mean anything because they were acquired during the ramp up to austenitizing temperatures and any vestige of meaning for those colors is erased during that process.

A heat affected zone usually means an area of metal that has been affected by heat and changed by it such as the temper of a hardened piece of metal being damaged by excessive heat that exceeds its tempering temperature, or a zone of steel that was heated by laser or plasma and experience a change in structure. That doesn't apply in this case because the entire piece was being changed in structure because it was being austenitized, and at much higher temperatures than those colors were formed.

They're simply a vestige of the ramp up to austenitizing temperature that basically says "hey I was many hundreds of degrees on my way up to being thousands of degrees". I wouldn't read too much into it.
 
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The most important factor that influences the creation of the HAZ is thermal diffusivity. Technically speaking, this coefficient depends on thermal conductivity, density, and specific heat of a substance. Materials that show a high thermal diffusivity are able to quickly transfer variations in heat, rather than heat itself.

In other words, if a material demonstrates high thermal diffusivity, it cools faster, and HAZ is reduced. Conversely, lower coefficients mean that the energy cannot be drained quickly, and the HAZ will be wider. For instance, 304A-grade stainless steel has a thermal diffusivity of 4.2 mm²/s, much lower than structural steel (11.72 mm²/s).

From the production process standpoint, the extension of the HAZ depends on three factors: quantity of heat applied, duration of exposure, and area affected . If large amounts of energy are provided for a long time and with wider beams, the HAZ is larger.

This explains the reason that, regardless of the material being cut, any cutting technique causes a different effect:

- Shearing and waterjet cutting do not provoke a HAZ because they do not overheat the sheet metal.
- Laser cutting generates the smallest HAZ among all thermal cutting techniques because it applies heat on a very small area.
- Plasma cutting generates an intermediate HAZ because the plasma pulse is wider than a laser beam. Higher currents allow for a higher cutting speed, reducing the duration of exposure and the width of the HAZ.
- Oxyacetylene cutting generates the widest HAZ of all thermal cutting systems because of the intense heat, slow speed, and wide flames.

Heating caused by the welding or cutting process and subsequent fast cooling result in both chemical and metallurgical alterations. Oxidation is the most noticeable and immediate change, and it is also responsible for the brightly colored bands. A light surface nitriding also can occur, resulting in an increased hardness and decreased weldability of the metal.

Another common effect is corrosion, derived from stainless steel’s sensitive nature. Intense heat causes the precipitation of chromium carbides around the grain boundaries. In these areas, chromium content drops below 10.5 percent, and steel loses its ability to form a passive film and relinquishes its ability to be stainless. The result is the so-called intergranular corrosion. In extreme cases, metal will turn black.

High temperature also can provoke hydrogen embrittlement. Gas diffuses through the metal and creates a strong pressure within the lattice, reducing its tensile strength and toughness. If the hydrogen gas is not removed, it can cause spontaneous cracking even 24 hours after heating.

From a metallurgical point of view, heat generates localized hardening. In some circumstances, austenitic stainless steel can turn into martensitic, increasing its hardness as well as its brittleness. In other cases, heated metal can become weaker.

But given the genre of the knife, whatever effect the HAZ has on it in this particular instance I would believe to be negligible. As all your knives Nathan, it is beautifully made, but if I have a choice, I'd go for one without the THINNER... umm... fuller. :D

You can if you wish make one without it and send a sample of EACH to me here in Aus where I can test them both for you... it would be a completely UNBIASED test, I assure you... and there'll be no charge for the testing.

So when will you be shipping them? :D
 
There is no thermal cutting process used, they're milled.
 
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