The "Ask Nathan a question" thread

Grenock

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When I was a kid I wanted to be an inventor when I grew up. I also had a penchant for knives and sharp objects. I made my first knife when I was about 12, it was a crummy dagger made from a file on a bench grinder. I was one of those kids that grew up outside a lot and spent as much time in the woods as I could. One of my favorite tools was a machete. I had two, and I attempted to reheat treat the one that was soft and wouldn't hold an edge in the wood stove and quenched it in a bucket of water. surprisingly it didn't turn out much worse than what it started as, I'm pretty sure it wasn't heat treated in the first place.

I was working as a bicycle mechanic when I graduated high school in 93 and went to North Carolina State University. My aesthetic skills were stronger than my math skills so I went into the School of design rather than the School of engineering and got a degree in industrial design, which is product design. I have been working as a bicycle mechanic, but there were more bicycle mechanics than there were bicycle shops near the NC State campus so I found work at a local manufacturer who needed some design and engineering work and a machinist. When I graduated we moved that machine shop down to a facility we were opening in Georgia where I helped set up a pretty big contract manufacturer and worked there as a design engineer for years. About this time I put my own shop together and I was doing tool and die work and fixtures and fab work. I bought my first CNC in 2001 and it was pretty much the only CNC in town. I moved back to North Carolina to work as a design consultant for an engineering contracting sales rep company. This is where I really got into advanced plastic product design and mastered the CAD side of the CAD cam tools. We used my machine shop for prototype and development work for years until building our own lab. We got a couple haas mills and a big router and started some production too. Before long we were manufacturing quite a bit I had a crew of people and we were building stuff. My own shop had also grown to have pretty substantial capabilities. I was tinkering around with knives this whole time. At some point I started changing over our capacities to be production oriented rather than prototyping and started producing knives in volume utilizing ergonomic insight developed in a career making handheld products and advanced metallurgy learned over the course of many years of interest and reading but very little formal education on the subject. I moved away from that consulting position gradually over time and here we are. My shop has five machining centers and we produce a variety of products but the majority of our work now is knives.
Hey boss, you should just go ahead and make a sticky out of this post.
 
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I don't want to encourage a lot of folks to send stuff back in for a "spa treatment" because I'm not really in the business of refurbishing old knives. If someone has a knife that needs some work they can return it. But don't expect it to return "factory new". So, if someone hits a big rock or some barbed wire buried in a tree with a chopper please return it (don't try to grind anything really big out dry with powered tools, you might ruin the temper). If you pry a big staple with your EDC and snap the tip, please return it to be re-pointed. If you bust a scale, please return it or request a replacement. I try to take a common sense approach and there are generally no charges other than return shipping. But if it has scratches in the finish that's part of being a user grade knife and I prefer not to rework old work if I can avoid it.

As far as sharpening is concerned, I understand that many people are not well equipped to handle a large sharpening job and need help. While I don't want to get into the sharpening business, if a person needs something I made sharpened I'll usually do it for the cost of return shipping. Obviously, if too many people start taking me up on that and it becomes a common thing I'd need to ask for something $$ , but so far there hasn't can You help me find a real forged handmade double bladed Viking axe? I have been targeted by several frauds and now I’m really lost. I need a nice gift and willing to spend up to 800$ if it’s real but I can’t tell anymore.. or ever for that matter
 

Casinostocks

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^ I don't know if this poster is legitimate or what, but this seems to be the gist of the Q as deciphered from Nathan's reply to Justin back in Aug 30th 2016:

Can You help me find a real forged handmade double bladed Viking axe? I have been targeted by several frauds and now I’m really lost. I need a nice gift and willing to spend up to 800$ if it’s real but I can’t tell anymore.. or ever for that matter

Just doing my public service for today.

ETA: seems like to be asking about an axe all over the forum today, so must've stumbled upon us somehow through the new posts showing on the front page!

#stillnotnathan
 

bluemax_1

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^ I don't know if this poster is legitimate or what, but this seems to be the gist of the Q as deciphered from Nathan's reply to Justin back in Aug 30th 2016:



Just doing my public service for today.

ETA: seems like to be asking about an axe all over the forum today, so must've stumbled upon us somehow through the new posts showing on the front page!

#stillnotnathan
Probably did a general search for 'axe' and pulled up posts about the CPK axe discussion.
 
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Probably did a general search for 'axe' and pulled up posts about the CPK axe discussion.
I’ve been hunting for days I spent 6 hours last night. I really want something special I am sorry for interrupting I have had no luck only dishonest companies with false advertising and I thought I could find the tTRUTH on her for certain
 

Casinostocks

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I’ve been hunting for days I spent 6 hours last night. I really want something special I am sorry for interrupting I have had no luck only dishonest companies with false advertising and I thought I could find the tTRUTH on her for certain

Axes are not a specialty of Carothers Performance Knives, if you would like to spend some more time reading and researching this thread:

https://www.bladeforums.com/threads/axe-please-educate-me.1746330/

It seems that you are raising some flags eyebrows already on the Fiddleback Forge sub-forum so if your inquiries are genuine, i.e, not trolling, you may wish to follow the decent advice which your were given over there by delving into the forum where you will be best serves asking about axes. I would like to make another suggestion; throwing phrases around like "fraud", dishonest companies" and "false in advertising" are all topics best served here:

https://www.bladeforums.com/forums/feedback-the-good-the-bad-the-ugly.699/
 

Odog27

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You’ve likely garnered their attention with your bot decimating K-18 project coming to fruition.
You should probably watch “Maximum Overdrive” and some of the “Terminator” movies for tips on what you can do to protect you and your family.
They are relentless.
 

jlauffer

Tempt not the Blade
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You’ve likely garnered their attention with your bot decimating K-18 project coming to fruition.
You should probably watch “Maximum Overdrive” and some of the “Terminator” movies for tips on what you can do to protect you and your family.
They are relentless.

Be careful getting anything out of a vending machine:eek:
 

Big DJ

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Good morning Nathan, I'm wondering about the heat treatment on the AEBL DEK1's. I have "a few" of your D3V knives and have no experience with the AEBL.
 

AR-Trvlr

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Good morning Nathan, I'm wondering about the heat treatment on the AEBL DEK1's. I have "a few" of your D3V knives and have no experience with the AEBL.
Have you looked through the encyclopedia?
https://www.bladeforums.com/threads/aebl-vs-delta-3v.1653015/
Never mind. There isn’t actually much in the way of technical info there. Nathan has probably addressed it before, but I don’t have a link to a specific post.
 

AR-Trvlr

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Found a couple of his posts:
3V has extraordinarily good impact resistance and ductility at relatively high hardness and high abrasive wear resistance due to the high vanadium carbide volume fraction (one of the hardest carbides). The Delta protocol addresses its edge stability issues helping it achieve a durable edge at fine geometries making the steel both tough and strong in a knife edge application making the finished product an extremely useful highly durable cutting tool. Durable in both a large scale (the knife is practically unbreakable) and at a small scale (the edge will tolerate abuse without chipping or rolling). A side effect of the Delta protocol is improved corrosion resistance due to the free chromium making it nearly stainless.

Optimized AEBL is very tough for a stainless and has a fine edge stability almost as good as a simple carbon steel. It is very close to an old school simple steel (tough, easy to sharpen, takes a very keen edge) yet has good corrosion resistance. There are other more complex stainless with better corrosion resistance, but they're icky with that mushy crumbly edge that needs to be obtuse to keep from blunting when pressed into hard work. AEBL is a less expensive material than 3V and being a simple steel the heat treat process is a simple anneal, pre-quench, austenitize, cryo and tempers, which is less involved than the Delta protocol and more affordable. It's a good steel for non-knife-nuts because it is more adorable (edit affordable) and easy to maintain.

AEBL has good corrosion resistance compared to a carbon steel but it's not great compared to some other stainless, but this is necessary to retain its world class edge stability. Its edge retention is pretty good due to the high hardness, but it is not in the same league as Delta 3V because it doesn't have the abrasion resistance. It is easy to sharpen though and rewards a skilled sharpener with a fiendishly sharp edge with very little fuss. D3V can also get extremally sharp due to my fine grain, high hardness, uniform microstructure with minimal RA and other messy structures and 3V's ultra fine carbide, but it takes more time due to the resistance to abrasion.

AEBL is like a simple carbon steel which many wood workers prefer because they can get it screaming sharp easily and it can stabilize an edge at very narrow sharpening angles. But I would choose D3V because wood is often abrasive and I don't want to have to fool with sharpening my knife during a project and the wear resistance of 3V and the edge stability of our 3V makes a better choice for me.

There is some disagreement out there in the innerwebs about the toughness of AEBL with some claiming it is very tough. It is relatively tough. It is nowhere near Delta 3V. You will never break a Delta 3V knife in anything remotely resembling normal use including moderate prying or whacking it with a wooden baton. The same is not always true for AEBL. It is tough but your margin for error is less with AEBL.

Yeah, we're running the AEBL and D3V the same. They're HRC 60.5, ~.018" before sharpening, 20DPS, 6.2 ounce, 4.5" blade length, 9.125" total length

I don't care what steel costs, the cost of the steel amounts to little more than a rounding error. I'm going to use the best material available for an application, cost doesn't figure into it.

I also don't care much about what steels are fashionable at the moment.

People might think I need my head examined for choosing AEBL because it does not have some of the pedigree of other particle super steels, but I have selected it because of its combination of superior edge stability and retention, good toughness, and decent stain resistance.

The AEBL is aimed at jarheads, not knife nuts. The Elmax is equally tough and has better wear resistance, but in rough use (clacking it against hard stuff) it goes dull just as fast as AEBL and the average enlisted man can't sharpen it. It's a matter of edge stability vs wear resistance. The AEBL performs better in edge stability and is easy to sharpen and makes a better choice for someone who wants a tough low-maintenance knife.

Our HT for AEBL is multi step and involves complex cryo and shares many similarities with the Delta protocol. We did make an effort to optimize it.

3V was a steel with marvelous potential that was being heat treated with a process optimized for tool and die, which has thick sections, risk of cracking and distortion, and the application calls for minimal dimensional changes. My knives are measurably longer after heat treat due to expansion from martensite, which would be a problem in tool & die. These things lead to a slow quench, intentional stabilized retained austenite and utilizing the secondary hardening hump for the T&D application it was designed for. This gives good performance in a stamping tool but a chippy mushy edge when used in a knife due to softer carbon lean martensite and areas of RA that behave like the perforations in a sheet of postage stamps. So you end up with a steel that will tolerate rough use except the edge would go dull from poor edge stability. 10-15 years ago I was among a few makers buking the trend and utilizing heat treats that differed greatly from the data sheets. I used to get called out for blasphemy. I started with D2 but gravitated to 3V due to a better balance of properties.

3V is a complex steel with complex interactions. For example, an attempt to use a low temp tweak without addressing the RA through quench rate and quench depth could easily lead to worse results. The condition of the steel going into HT is an important variable. There are a couple aspects of the Delta protocol that are not intuitively obvious and work for 3V but not D2. I tweaked 3V over the course of several years before finally going through the laborious process of identifying and evaluating the effect of minor changes to a bunch of interconnected variables. I started having the steel made specifically for me buying entire "melts" and owning the entire heat lot. At this point I felt comfortable saying that my 3V with my HT is demonstrably different (and better) than the industry standard. They're really not the same thing. It is changed (Delta). So I added the Delta prefix to differentiate it from my earlier work and from other people's 3V. This was important because a lot of people had preconceived notions about the alloy and its ability to shrug off damage from rough use. I didn't want my work pre-judged from people's experience with the alloy from other makers. This is why it was named.

AEBL is a relatively simple steel. I'm not doing anything revolutionary with it. Doing a competent job on AEBL isn't rocket science. There is some low hanging fruit and I've picked it. That doesn't warrant a special name.
 
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