High cutting performance knife

BluntCut MetalWorks

BluntCut MetalWorks

Knifemaker / Craftsman / Service Provider
Joined
Apr 28, 2012
Messages
3,462
I have an un-reasonable expectation, perhaps you guy can help judge & tell & maybe medicate me ;)

Recently I made a 21cm W2 kitchen knife @ 65+rc (tested at 67rc - guy, yes it's true, since fatalistically I only tempered this knife at 300F). almost zero grind w/ behind edge thick around 0.005". 7-10 dps white compound stropped edge.

What do you think, if I put it through this test (will video it):

* end grain cutting board
1. free-standing-tomato slicing
2. 10 cuts 1/2" sisal rope
3. 10 cuts 2" wide 1" thick stack of cardboard
4. 10 slices 1/2" dia pine rod - cross grain or at least 80 degrees angle
5. 10 cuts paracord with pork rib bone as backing

OK, after a quick fluff off any dangle bits on the edge using a carbide scrapper or spine of another knife. I want/expect it smooth slices newsprint at 45 degrees and perform tomato slicing. Am I wishful thinking.

Well - your thoughts & predictions?
 
I'm not a steel maven, but does W2 chip easily? I love the very thin blade profile, but I'm concerned that at such high hardness it will chip.
 
Almost all steels are brittle at 64+rc couple with thin geometry, usually big nasty chips. Says, if S7 can harden to 66rc and 0.01" behind edge and 10dps, it would chip since its renown toughness won't extend at upper hardness limit. W2/W1/1075/1095/52100/3v/elmax/etc.. won't support this test. unless - hahha if I pull off this stun. I would obligate to pass this knife around - with hardness testing allow to verify. My 52100 probably will pass this test at 65rc but not harder. Test steps 4 & 5 put a lot micro incidental lateral force on the edge.

eb1118 said:
I'm not a steel maven, but does W2 chip easily? I love the very thin blade profile, but I'm concerned that at such high hardness it will chip.
Click to expand...
 
I am just a bit of stir-crazy from too busy working on cloud ERP app. Here is the test candidate, balanced on a pencil. Pic at an angle to show hamon.
IMG_4279.jpg
bdmicarta said:
I cringed when I read "pine rod", so that tells you my expectations of it.
Click to expand...
 
Do those pine rod slices have to cut the dowel in half?

Should be a good test for an edge that thin.

Nice looking knife!
 
bluntcut said:
I have an un-reasonable expectation, perhaps you guy can help judge & tell & maybe medicate me ;)

Recently I made a 21cm W2 kitchen knife @ 65+rc (tested at 67rc - guy, yes it's true, since fatalistically I only tempered this knife at 300F). almost zero grind w/ behind edge thick around 0.005". 7-10 dps white compound stropped edge.

What do you think, if I put it through this test (will video it):

* end grain cutting board
1. free-standing-tomato slicing
2. 10 cuts 1/2" sisal rope
3. 10 cuts 2" wide 1" thick stack of cardboard
4. 10 slices 1/2" dia pine rod - cross grain or at least 80 degrees angle
5. 10 cuts paracord with pork rib bone as backing

OK, after a quick fluff off any dangle bits on the edge using a carbide scrapper or spine of another knife. I want/expect it smooth slices newsprint at 45 degrees and perform tomato slicing. Am I wishful thinking.

Well - your thoughts & predictions?
Click to expand...

That's 1/8 of a mm of edge thickness before sharpening - your BS will give a bit of a convex to it - hmm, that's gonna be interesting. I would expect chipping during step 5 since highest risk of lateral movements.

Nice knife !!
 
Last edited:
bluntcut said:
I have an un-reasonable expectation, perhaps you guy can help judge & tell & maybe medicate me ;)

Recently I made a 21cm W2 kitchen knife @ 65+rc (tested at 67rc - guy, yes it's true, since fatalistically I only tempered this knife at 300F). almost zero grind w/ behind edge thick around 0.005". 7-10 dps white compound stropped edge.

What do you think, if I put it through this test (will video it):

* end grain cutting board
1. free-standing-tomato slicing
2. 10 cuts 1/2" sisal rope
3. 10 cuts 2" wide 1" thick stack of cardboard
4. 10 slices 1/2" dia pine rod - cross grain or at least 80 degrees angle
5. 10 cuts paracord with pork rib bone as backing

OK, after a quick fluff off any dangle bits on the edge using a carbide scrapper or spine of another knife. I want/expect it smooth slices newsprint at 45 degrees and perform tomato slicing. Am I wishful thinking.

Well - your thoughts & predictions?
Click to expand...


You won't really know until you test it.....
 
Thanks guy!

This afternoon while on break, at my desk - I tried to make a thin slice through a 5/8" poplar rod/dowel like a stiff carrot. *bad news* with strong arm and put lean body into it. half way through, the edge exited the rod, the downward pointing tip slammed into oak desk, twisted the blade, then the back end slanted edge laterally hit a 90* angle edge of a hardwood backing with a whole lot of pressure. Edge (2" from heel) suffered a 1/3" vertical crack. *good news* blade didn't split in half; didn't scare nor hurt me; now I can do hard tests w/o worry and good excuse for me to finish up its backup twin (except it's 24.5cm instead of 21cm) W2 gyuto and lastly I can try different woods for handle.

I can't find 1/2" pine rod, so I bought 7/16" poplar rod instead. reasonable substitute since poplar is a little bit harder than pine. I plan to press edge down into rod & roll-the-rod to make 10 cut cross grain. Let me know if you guy know a better way.
 
Pork rib bone is quite hard, so cutting paracord on it almost like cutting on granite. Exactly, I use BS (Balanced Strop) to refine and add a micro convex bevel to the edge. I guess I wanted to know what a thin & sharp & max rc edge can withstand and damage sustaining. I expect this knife still be serviceable in the kitchen after this test set. but if If I chop this edge through the bone, probably will get 2-3mm chips... bye bye knife.

awestib said:
That's 1/8 of a mm of edge thickness before sharpening - your BS will give a bit of a convex to it - hmm, that's gonna be interesting. I would expect chipping during step 5 since highest risk of lateral movements.
Click to expand...
 
I am pleased with the result. Thanks for watching & comments.
[video=youtube_share;8gvVgF9RG6A]http://youtu.be/8gvVgF9RG6A[/video]

It deserves a save, right? ;)

fix chip.jpg
 
Thanks for sharing bluntcut.
So the conclusion is then either drop down the rc to 60-61 and/or change the apex angle with a bit more substance behind the edge. The advantage of a thin kitchen knife is obvious so maybe the first?

Plus, don't forget, we all love sharpening so a knife that never gets dull or cuts like laser even if dull is a "nightmare" ��
 
You must log in or register to reply here.
Back
Top