185mm Petty/Utility in Elmax with wa handle

[BluntCut MetalWorks]

I'm having fun with my backyard knife making. Turned an Elmax bar stock into this petty. Heat treated using a propane torch + charcoal + electric stove top. Used a Koa wood from a thrift store serving tray for a handle.

It took a long time to grind the blade into shape after HT. I was aimed for a laser distal but reality of grinding hard alloy stopped it here.
I'll performance test this prototype along side with a Yoshikane 180mm skd-11 64rc petty.

Quick stats
OAL: 320mm
Blade length from heel: 185mm
Steel: Elmax
Handle: koa, octagon wa
HT: backyard, estimated 60rc (w/o subzero nor cryo quench)
Height: 37mm
Balance: 15mm from heel
Thickness: heel: 2.5mm; 1cm from tip; 1.2mm; 5mm behind-the-edge: 0.56mm



What's your frank/blunt opinions?

Thanks

 

[Mike L.]

My son is a professional chef. I can have him evaluate/test it if you want.

 

[BluntCut MetalWorks]

Thanks Mike! I'll keep this in mind, especially for version 2.0 knives, those that passed my low-standard first. This knife distal taper is incomplete, ie. messeup geometry. Plus the bar stock wasn't tall enough, so I couln't create a proper the edge profile, end up too flat. I will evaluate the distal tip and Elmax sharpness/toughness/retention/feel relative to the Yoshikane petty.

If this knife manages to surprise me with good performance, I might consider doing a pass around.

 

[Mike L.]

You might want to take a look at www.kitchenknifeforums.com for some ideas and suggestions.
I'm not a chef or a kitchen knife expert, but a lot of the guys who post there are exactly that.

 

[BluntCut MetalWorks]

You might want to take a look at www.kitchenknifeforums.com for some ideas and suggestions.
I'm not a chef or a kitchen knife expert, but a lot of the guys who post there are exactly that.

Thanks Mike!

Yes I would do that, unfortunately DaveM disabled my KKF account a few months ago - no clues why.

 

[james terrio]

Turned an Elmax bar stock into this petty. Heat treated using a propane torch + charcoal + electric stove top. Used a Koa wood from a thrift store serving tray for a handle.

I hate to break this to you, but you have essentially wasted a bar of very good, and rather expensive steel. I'm sure it got "hard" to some degree or another, but I guarantee you it's nowhere near it's full potential. For the love of Pete, please do not test that knife and think it's representative of what Elmax can and should be.

High-alloy steels like Elmax require pretty precise HT. Send them to a pro. If you're that limited in the HT tools and procedures to do it yourself, stick with 1080 or 1084. You should be able to get pretty close to their best potential.

 

[BluntCut MetalWorks]

I hate to break this to you, but you have essentially wasted a bar of very good, and rather expensive steel. I'm sure it got "hard" to some degree or another, but I guarantee you it's nowhere near it's full potential. For the love of Pete, please do not test that knife and think it's representative of what Elmax can and should be.

High-alloy steels like Elmax require pretty precise HT. Send them to a pro. If you're that limited in the HT tools and procedures to do it yourself, stick with 1080 or 1084. You should be able to get pretty close to their best potential.

Thanks for the feedback James! You're right about precise ht requirement, no where close in my case.

This Elmax blade was over-heated and poorly quenched & tempered. I hope/targeted that with a backyard ht, I can get 60-70% of Elmax potential. I would like to find out, how would this 60% (assumed potential) Elmax compares (subjective for now) to known good knives (Yoshikane, Blazen - fruit knife). So far, I used it to prep for 3 meals. It done well.

My primary goal is to see if high-alloy (so far: elmax, 3v, m4, s90v) steels are accessible to non-pro backyard self-contain knife making. Also not to mock pros but rather broaden the public appreciation to products created by pros. We won't get there unless ppl are using/making(gateway) high-alloy knives. Why would ppl want a 400hp v8, introducing for test drive... an inexpensive home/cheaply built 240hp (60%x400)v8 Time to drop an engine into a Fred Flintstone's car.

Is is wishful thinking?

 

[james terrio]

Is is wishful thinking?

In a word, yes. It's definitely a waste of money. I understand your approach, and it's an interesting concept. But to use your hot-rodding analogy, the problem is this: you're not over-building a cheap stock motor to push it as hard as you can; you're taking an expensive, blueprinted racing motor and plugging up at least one of the cylinders, running it on stale gas and dirty oil, and driving with your eyes closed.

This Elmax blade was over-heated and poorly quenched & tempered.

Actually, I doubt you got it hot enough, and I'm entirely certain you didn't keep it at the right temperature for long enough to get all the
elements into solution. Elmax needs something on the order of 2000F with a soak time of 30 minutes to austenitize completely. It needs to be tempered at between 390-480F (depending on desired final hardness) for two cycles of two hours each. If you can do all that with a propane torch, charcoal and electric range, you're really onto something. That's not even taking into account that it benefits from a very cold final quench (liquid nitrogen or dry ice) to deal with retained austenite.

I hope/targeted that with a backyard ht, I can get 60-70% of Elmax potential.

I'd be very surprised. How would you even know, without a properly-HT'ed Elmax blade of the same geometry to compare it to? Even a calibrated Rockwell tester won't tell you what's going on with all the chromium, molybdenum and vanadium (whether they formed carbides and are doing you any good).

My primary goal is to see if high-alloy (so far: elmax, 3v, m4, s90v) steels are accessible to non-pro backyard self-contain knife making.

You can certainly shape, drill and finish any steel you want with nothing but hand-tools. But I don't know of any way to properly deal with high-alloy steels like those, short of spending a couple grand on a good kiln and quenching set-up... or spending $30 to have them properly HT'ed by a firm like Peters' or Bos. I send my blades to Peters' in batches of 10-25 and it ends up costing me about $8/blade, including shipping both ways. Is a $20-50 piece of steel and all your time/labor worth an extra $8 to know it's as good as it can be?

Very simple and inexpensive backyard set-ups are used all the time to make very good knives out of simpler steels like 1084... think of that as your shade-tree mechanic 280HP V8.

I do applaud your willingness to think differently and experiment. :thumbup:

 

[BluntCut MetalWorks]

Many great points, :thumbup: James!

I tinker with max 10 blades per steels so sending out and request different tempered hardness would be kind-of expensive, plus long turn around time.

RichardJ email me and also questioned whether temperature was hot-enough. I really don't know. Except I saw decarburized surface, the clean surface peeled back a couple thin layers and after quenched there is a soft thin layer on surface. Maybe my inexperience and mis-interpreted this as over-heated. For hardness test, I use tungsten carbide tip (cut from a saw blade) to scratch/dent the blades and compare the scratch/dent to known blades (my ref blades: bm940 s30v, endura vg-10, stretch cf zdp-189, gb cpm-m4, plus my homebrewed 52100 knives). Later on, I plan to sub-zero quench to keep high % of retained austenite. But it's another impractical/bother for tinkerers.

Ultimately, how these blades perform will tell, hopefully not a complete waste of time & materials. In any case, yours & others educate-points and feedbacks are very much appreciated.

edit: btw here a pic of a cracked m4 blade during quench and I broke it batonned wood - the surface layer where I thinked decarbuization occurred