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So, I've been immersed in kitchen knives for months and months now, lol. Part of my making process involves thermal cycling the forged and cleaned up blade blanks in a controlled round of heats, that ends with a through hardening and spheroidized anneal for 2hrs at a much lower temperature. The last batch I have been working on ended up being 18 knives in total (I tossed a couple kiridashi and EDC knives in there for Christmas gifts).

 

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Needless to say, thermal cycling 18 knives was a bit time consuming, so...in between I decided to make a knife for myself out of Aldo's oldest run of W2.

 

The idea was for a heavy use hunting/survival/camp knife. I wanted something equally efficient at anything from processing game (from squirrels to elk), to making feather sticks. I decided on a 6" blade length, only 1.5" wide...with a short flat area and long belly. Thickness would be +/- 5/16" with moderate forward distal taper, and a 3/4 flat grind. The top 1/4 would be forged back, creating a tall diamond cross section. This would provide stiffness and strength, while giving a slight weight reduction to the knife. I decided a clip point with a false edge would give easier penetration, and making the clip only a couple inches long would give me a nice, long flat spine for batoning and striking a ferrocerium rod. There is an equal distal taper to the butt. The handle area also tapers in thickness from spine to edge. The entire knife was forged to shape, including all tapers, as well as the bevels. The only parts ground in are the secondary bevels (which were initially forged in), and the clip.

 

 

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The first order of business was to sketch out my ideas. I'm a firm believer in form following function, and so in my sketching I try to incorporate the things I know I will need. I decided I liked the middle profile the best, and got to it.

 

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A few hours work gave me this.

 

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Rough ground in bevels, spine and grip around the handle rounded and polished for comfort and rust resistance, and you can see it fits my intended profile nicely :). From here I still needed to grind in the clip, then heat treat.

 

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Finished rounding of the spine over the handle, with a compound geometry transitioning to the flat spine of the blade.

 

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I truly love hot work! This entire blade was forged down by eye from a 1 1/2" x 3/8" piece of W2. I always challenge myself with every blade...'just a little flatter than the last one, a little truer...don't take it to the grinder Cris!...you can forge out that finger choil!'. I use a post anvil, and I have three hammers, of which I really only use two. My main hammer is a forward weight with a slightly domed face, and my second hammer is a cheap cross peen with a blunted face on the peen, and a heavily rounded striking face on the vertical axis (it acts like a very, very, VERY blunt straight peen). This entire blade was forged with those two hammers and my forklift tine post anvil.

 

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Clay layout and thickness. C'mon...this is me. You just KNEW it would have to be differentially hardened, right??

:)

 

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And...success! On the first try even. Most blades require at least two attempts for me...some require three, and others...well, we won't talk about those.

 

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This is my first knife ever with plunge cuts. Generally (on my EDC knives) I maximize edge length and sharpen right to the choil, but on this knife plunges were mandatory. Blood, mud, rain, and other outdoor wilderness type environments can make a knife a bit slippery in hand. The last thing you want is to lose a finger or severely cut yourself when you're hundreds of miles from civilization! On this knife, with the forged finish...I wanted them clean and well done (meaning matching in depth, angle, and precision), but a bit rustic as well. I think it worked out nicely.

 

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This is where it sits now. I haven't decided on a handle arrangement...but I think scales will be a requirement. A wrap is just too difficult to care for in the field. Again...mud, blood, moisture...etc, can easily get trapped in the wrappings. I think partial scales would be really cool...and its a requirement that the polished area of the spine and grip protrude from the profile of the scales (I know...that just compounded the difficulty by about a hundred fold). In addition, the butt of the knife is hardened as well, and so needs to be left open to display the line. I have a number of very high quality woods to choose from (all stabilized), including some really nice claro walnut, snakewood (I've been dying to use this on something!), bog oak, buckeye burl...and as I said, a number of other woods. Choosing has been difficult up to this point, lol. Feel free to chime in if you have any cool ideas :).

 

Anyway, this knife is incorporating a lot of firsts for me. The profile, being forge finished, plunges, and scales...are all first time efforts. It's been really satisfying for me that it's coming together so cleanly and without issue. As bladesmiths yourselves, I know you all can appreciate that in a way my customers can't, lol.

 

So there we are...thanks for looking guys and gals! As always, commentary, critique, and most of all criticism...are always appreciated!

 

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Here I was thinking it was all superbly done, then you mention the differential hardening line on the butt. That easily pushes it over the top! Got any stag to make scales out of? For a field knife that always just feels right to me.

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It looks good, I'm thinking the bog oak would look good with the forge finish. But that's just my opinion.

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Thank you gentlemen!

Caleb, all of my EDC type knives with this profile handle have hardened butts as well:

 

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That's my other personal knife :).

 

As far as the how...tell me how you think you would do it if I asked you to as a customer, and then I'll tell you how I actually did it :).

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As for the handle materials...I don't have stag...though I thought about it. I like the idea of the bog oak as well, though even stabilized it's a very brittle wood to work with. The claro walnut is classic...and if i do it right the 'shotgun butt' look could finish off the knife well. The snakewood is just flat gorgeous, and the nice warm, deep red tones of it would be classy also.

 

I'm just not sure yet.

 

Here's a piece of that walnut with a light, 600 grit pass on the grinder to show the figure:

 

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And here's a few other pieces. That black dyed mango was a thought as well, but it's reserved for two kitchen knives, lol:

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I'll probably photoshop up some mock ups to see what I think might look best and go from there :).

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Those are beautiful and inspiring sir. I really enjoy seeing your take on the different styles of knives.

 

Also, if it were me hardening the butt, I would heat the handle end first without clay and either dip it in as far as I want, or really centralize the heat to the very end of the butt and dip fully, both scenarios without clay since shallow hardening steels work off of the activity of the water alone, and yours looks that way without the influence of clay.

 

Then as I were ready for HT of the blade itself, I would wrap a damp rag around the base of the handle and grasp it with my tongs and work the steel until I got it to temp...but this way doesn't take into account that the steel will have to soak as you use W2...

 

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Slash all that up there except for the praise.

 

So for W2 I would soak and HT the blade first until I had the hamon and hardness I wanted. Then I would wrap the entire blade portion in a wet rag, and either use a torch, or dare use my coal forge, and centralize the heat to the butt until it hit the 1450 and quench. Since it is the butt, no worries about carbides.

 

So how did I do?

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Those are beautiful and inspiring sir. I really enjoy seeing your take on the different styles of knives.

 

Also, if it were me hardening the butt, I would heat the handle end first without clay and either dip it in as far as I want, or really centralize the heat to the very end of the butt and dip fully, both scenarios without clay since shallow hardening steels work off of the activity of the water alone, and yours looks that way without the influence of clay.

 

Then as I were ready for HT of the blade itself, I would wrap a damp rag around the base of the handle and grasp it with my tongs and work the steel until I got it to temp...but this way doesn't take into account that the steel will have to soak as you use W2...

 

~~~~~~~~~~~~~~~~~~~~

 

Slash all that up there except for the praise.

 

So for W2 I would soak and HT the blade first until I had the hamon and hardness I wanted. Then I would wrap the entire blade portion in a wet rag, and either use a torch, or dare use my coal forge, and centralize the heat to the butt until it hit the 1450 and quench. Since it is the butt, no worries about carbides.

 

So how did I do?

 

 

Very good (on the second shot, lol)...except that I do in fact use clay. I want the hardening line on the butt to get progressively narrower towards the bottom, and clay is the only guaranteed way to control the placement.

 

Thank you for the compliments as well :). It's always nice, and often surprising to me to hear that others appreciate my aesthetic sense. Almost as surprising as it is every time I'm able to realize a knife that expresses it properly :).

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Thanks guys!

 

On the handle...this is a rough approximation of what I'm thinking (I used bog oak for the example wood). The contours will be different...this is just a faceted 'bevel/emboss' filter in Photoshop, but the profile of the scale and 3D effect of the filter gives you a general approximation.

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It doesn't look too bad! I'd play with it a little of course, on the knife...but in the end that may work. Domed nickel silver pins to match the polished contours of the spine and grip would top it off wonderfully.

 

Now...to see if I can pull it off lol. I've literally never done scales on a knife in my life.

James, that's not even the start of my wood collection, lol...

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That's a start :). I've got about three more shelves of various repeats lol.

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A few more handle options!

 

ClaroWalnut.jpg

Claro Walnut

 

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Spalted Oregon Maple

 

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Koa

 

Keep in mind, these are actual pieces of wood I have onhand...so I can get the wood to look VERY close to the pictures...as far as figure and color goes.

 

What's each of your favorite?

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If it were me, and it's not me so feel free to disregard... I made a chopper once with a similar wide tang with rounded edges and small scales, very much like you have planned, and it looked really cool but was uncomfortable to use, especially for chopping... ended up you needed gloves if you were going to use it for any extended amount of time. I would want the scales wider, almost as wide as the tang, and maybe a bit longer.

 

I vote for the bog oak.

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I second George's suggestions. The big rebate on the scales looks cool, but it will wear on the hand. Otherwise, that is one rockin' little knife. You are very talented, and creative.

kc

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I'll third everything George said - I find slightly rebated scales very comfortable and great for indexing and control, but too much and you end up with multiple small points of contact and insta-blisters. I'd suggest reducing the amount of tang showing at the edges by about 50%, and extend the scales at least half way through the finger groove, maybe a bit more, or the sudden reduction in thickness will make control awkward. and +1 on the bog oak...

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In my opinion the bog oak is really visually appealing and gives the knife a somewhat sinister look in that it will do what it was designed for with ease. Beautiful design and forging.

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This is a great post..beautiful work. On the second heat treating sequence ( the final quench)..how long do you hold at austenizing temperature..?. I do not see the Japanese knife smiths doing that with their white label steel ( I assume you are using some white paper steel ).....they seem to go to austenite from pearlite ( after bashing it a bit) then to quench. Pearlite converts to austenite faster than spheroidite in ferrite......are you seeing any residual spheroidite in your steel after quenching. Are you quenching in water...?..... and if so are you seeing any micro-cracking?

 

Thank you

 

Jan

Edited by Jan Ysselstein
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Thank you gentlemen!!

 

For what it's worth, I agree completely on the scales. The main reason I drew them up this way specifically was so that it was clear in pictures that they weren't the full height of the tang. My initial plan was actually to make it so only the rounded and polished areas protruded from the profile of the scales, but that didn't show well in the pictures. That said, I like the idea Jake suggested, of halving the width of the exposed flats by about 50% (as opposed to either as drawn above, or only leaving the polished area exposed). That gives me the rebate I want, and shows off a little of the forged flats also.

 

 

This is a great post..beautiful work. On the second heat treating sequence ( the final quench)..how long do you hold at austenizing temperature..?. I do not see the Japanese knife smiths doing that with their white label steel ( I assume you are using some white paper steel ).....they seem to go to austenite from pearlite ( after bashing it a bit) then to quench. Pearlite converts to austenite faster than spheroidite in ferrite......are you seeing any residual spheroidite in your steel after quenching. Are you quenching in water...?..... and if so are you seeing any micro-cracking?

 

Thank you

 

Jan

 

Thank you Jan!!

 

W1 and W2 are actually US steels. AISI W2 is what I've used here, as supplied by Aldo at New Jersey Steel Baron LLC. It's substantially different than the white steels, in that it is less 'pure' (there's residual alloying elements), and also has a specific amount of vanadium to pin the grain size and for carbide formation, and a bit of chromium added in order to provide grain refinement, toughness, some small amount of carbide formation...and to improve hardening characteristics. It's still a very shallow hardening steel in part due to the low manganese content. The Japanese White paper steels are also a bit higher in carbon content. All of this plays a big part in why I thermal cycle and heat treat the blades the way I do...versus the methods the Japanese are employing with the white steels. My primary goal in my heat treating process is carbide refinement and dispersion. Grain refinement is a natural effect of the process I use as well, but to me...with W2, carbide refinement and placement (in other words, NOT in the grain boundaries!) is more important.

 

To answer your questions specifically:

 

On the final hardening sequence, I bring the blade up to 1475°F (this number is for MY oven...I want to clarify that because I haven't calibrated this to real world numbers. I just know that this temperature using my thermocouple gives me the best hardness, toughness, and aesthetic results). Once it's stabilized, I hold the blade there for 10 minutes. When I'm satisfied that everything (except the carbides I worked so hard to refine and disperse) is in solution, I quench into room temperature Parks 50. The result is a blade that is very hard, and still quite tough. I am able to temper at much lower tempers than when I was hardening the same steel in my forge, and sharpen to a more acute edge angle as well...with no loss in durability. My old W2 blades were good (I received excellent feedback from customers and my own testing), but the new blades when properly cycled and hardened are like night and day.

 

I hope that helps :).

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Hi Chris.

(Thanks to your article on etching, I do my mark that way, instead of hot stamping these marks!)

 

The knife design is sleek, sharp and I like the contrasts of shiny blade, edges, etc. If it were mine, I would not skimp on the handle and go small. I would try to fit an outline just exposing the rounded edges and and pommel. I would round and shape the handle similar to Cold Steel's "Black Bear" model. ( palm swell, finger detent, if that makes sense).

You've already set boundries, now accent them. Bevel the front at the tang and at the back pommel, proportionately or as needed.

 

Don't ch'ya love opinions!

 

Gary T.

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Hi Chris.

(Thanks to your article on etching, I do my mark that way, instead of hot stamping these marks!)

 

The knife design is sleek, sharp and I like the contrasts of shiny blade, edges, etc. If it were mine, I would not skimp on the handle and go small. I would try to fit an outline just exposing the rounded edges and and pommel. I would round and shape the handle similar to Cold Steel's "Black Bear" model. ( palm swell, finger detent, if that makes sense).

You've already set boundries, now accent them. Bevel the front at the tang and at the back pommel, proportionately or as needed.

 

Don't ch'ya love opinions!

 

Gary T.

 

Thank you! I'm glad my tutorial could help you out!!

 

On the handle thing, do you mean this model?

 

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If so, I think that's way too much handle for this knife...for a couple reasons. First, about 3/4" of the butt needs to remain exposed. Because of this...if the handle extends too far into the finger choil...it'll look unbalanced. This can be mitigated by narrowing the scales some, allowing them to be longer without causing too much visual imbalance. For a full height tang, it leaves me a really narrow window for the handle to look 'right'.

 

That said, I'm definitely wanting to get enough material on there to 'sculpt' the scales. Just as you mentioned...palm swell, sculpted finger grip, and a slightly flared butt are all in my head.

 

I'll probably start a couple sets of scales this evening in pine. That way I can work out a profile I like, and sculpt it in a way that works. I agree completely that the knife is too complicated for slab side scales with some bevels cut in, lol. I may even end up doing some carving (another first!!) to break up the lines and make a larger set of scales work visually.

 

We'll see how it goes!

 

Oh, and as for opinions...I DO love them! That's why I absolutely ask for them every post I make :).

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Chris,

 

Thank you, that is very clear. I wonder if the residual carbides in the austenite will cut better if they are in spheroidal form or as grain boundary remnants....given there would be a trade off in toughness.

 

Jan

Edited by Jan Ysselstein
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Carl,

 

Thank you, that is very clear. I wonder if the residual carbides in the austenite will cut better if they are in spheroidal form or as grain boundary remnants....given there would be a trade off in toughness.

 

Jan

 

There is no measurable amount of austenite left at the cutting edge in W2, after hardening.

 

As far as having the carbides within the grain boundaries, or not...I'm guessing that there wouldn't be a lot of change in the aggressiveness of cutting. However...there are substantial...measurable changes in toughness as you said, as well as edge holding...since your edge won't be prone to microchipping from carbide fallout. Your very hard carbides are very fine, and are no longer sitting within the grain boundaries where they would weaken the edge.

 

Imagine it like a stone wall. You want all of your grains (the stone) small and evenly spaced. You do NOT want smaller stones floating around within the cement mortar (grain boundaries) for any reason whatsoever, as they substantially weaken the bond from stone to stone. Well mixed 3/8" concrete would represent a very fine grained steel, while a brick wall would represent larger grains. The concrete is absolutely the tougher of the two...but the second you start mixing too much sand (carbides) into the cement/mortar mix for either one, things quickly begin to fall apart.

 

I know that's an incredibly simplified explanation...but the analogy fits. Keeping carbides out of the grain boundaries is my primary goal when heat treating my steel. That's why the Japanese white steels are so very simple to heat treat. There is no alloying elements to form carbides with.

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There is no measurable amount of austenite left at the cutting edge in W2, after hardening.

 

As far as having the carbides within the grain boundaries, or not...I'm guessing that there wouldn't be a lot of change in the aggressiveness of cutting. However...there are substantial...measurable changes in toughness as you said, as well as edge holding...since your edge won't be prone to microchipping from carbide fallout. Your very hard carbides are very fine, and are no longer sitting within the grain boundaries where they would weaken the edge.

 

Imagine it like a stone wall. You want all of your grains (the stone) small and evenly spaced. You do NOT want smaller stones floating around within the cement mortar (grain boundaries) for any reason whatsoever, as they substantially weaken the bond from stone to stone. Well mixed 3/8" concrete would represent a very fine grained steel, while a brick wall would represent larger grains. The concrete is absolutely the tougher of the two...but the second you start mixing too much sand (carbides) into the cement/mortar mix for either one, things quickly begin to fall apart.

 

I know that's an incredibly simplified explanation...but the analogy fits. Keeping carbides out of the grain boundaries is my primary goal when heat treating my steel. That's why the Japanese white steels are so very simple to heat treat. There is no alloying elements to form carbides with.

 

That was incredibly insightful. Thanks!

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