But is it sharp?

gamma_nyc

gamma_nyc

Gold Member
Joined
Dec 1, 2007
Messages
713
Friends,

1) post your “But, is it sharp?” videos.

2) Share your prep method.

I’ll go first!

Spartan Harsey Folder, Saint Michael the Archangel, limited edition. They build a great knife.

1670256066983.jpeg

Sharpened using:
6000 grit on work sharp electric, then 8000 Naniwa, leather strop brown and green compound.

 
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The knife is a Takamura R2 gyuto that i sharpened a few years back for a pro-chef, who made the clip and sent me the link.

- Repairing the point of the knife (about 2 mm was broken off) was done on the Tormek by grinding the back of the blade until there was a new point.
- Flattening the old edge was also done on the Tormek T7 fitted with an SB-250 Black silicon carbide stone (by grinding off about 1/10th of a mm on the side of the stone.
- Sharpening to a tiny burr was done exclusively on a 15 micron diamond compound coated Paper Wheel.
- Deburring was done exclusively on a 0.25 micron diamond compound coated Paper Wheel.
- Rounding the heel of the knife was again done on the Tormek T7 (by grinding off a tiny bit of steel on the side of the stone.)
 
Another oldie (from 2013), a black ceramic knife slicing single ply toilet paper (torn apart 3-layer version)
Edge is polished up to 6 micron diamond compound on a Paper Wheel, measures ~25 degrees inclusive, and the keenness is just hairwhittling (only from the hair point towards the hair root, not vice versa)

 
Blade Lab said:
Made a $3 stamped grocery store knife razor sharp. Why? Because it was there. :)

Click to expand...
Thats really impressive on a cheap soft stainless knife, what did you do to it?

I sharpen similar knifes for family, they are the worst. I usually put them on a Crystolon, India and follow it up with a loaded strop to be sure all the bur is gone. About the only time I use a loaded strop with knifes. Down and dirty, out the door as soon as possible.
 
garry3 said:
Thats really impressive on a cheap soft stainless knife, what did you do to it?

I sharpen similar knifes for family, they are the worst. I usually put them on a Crystolon, India and follow it up with a loaded strop to be sure all the bur is gone. About the only time I use a loaded strop with knifes. Down and dirty, out the door as soon as possible.
Click to expand...
Thanks. I used my standard approach for the most part. Tormek with CBN 1000 wheel, followed by Japanese wheel, and then stropped on leather belts with Tormek compound. The secret (don't tell anyone!) is that, the cheaper/softer the steel is, the higher you have to go above the sharpening angle when stropping. In this case I sharpened at 15° and then stropped on the WS Ken Onion: two passes at 17.5° followed by two passes at 15°. Then a couple swipes on a hanging denim strop.
 
kwackster said:

The knife is a Takamura R2 gyuto that i sharpened a few years back for a pro-chef, who made the clip and sent me the link.

- Repairing the point of the knife (about 2 mm was broken off) was done on the Tormek by grinding the back of the blade until there was a new point.
- Flattening the old edge was also done on the Tormek T7 fitted with an SB-250 Black silicon carbide stone (by grinding off about 1/10th of a mm on the side of the stone.
- Sharpening to a tiny burr was done exclusively on a 15 micron diamond compound coated Paper Wheel.
- Deburring was done exclusively on a 0.25 micron diamond compound coated Paper Wheel.
- Rounding the heel of the knife was again done on the Tormek T7 (by grinding off a tiny bit of steel on the side of the stone.)
Click to expand...
This sharp, is it grind in a very small angle like 5 or 10 degs and very thin blade. I don't see knives that grind at even 15deg or larger can be this sharp.
 
alan0354 said:
This sharp, is it grind in a very small angle like 5 or 10 degs and very thin blade. I don't see knives that grind at even 15deg or larger can be this sharp.
Click to expand...

The edge angle i put on this Takamura measured ~20 degrees inclusive, as lower than that on SG2/R2 stainless steel @ ~63-64 HRC won't hold up in this guys professional use.
The owner's rank in the commercial kitchen is Chef de Partie (just below head-Chef and sous-Chef) and he and his team are responsible for prep cutting all the meats, vegetables & patisserie ingredients.
He is one of the guys that provides me with detailed feedback on edge performance & edge longevity, which i then use to try to improve upon my edges.
 
kwackster said:
The edge angle i put on this Takamura measured ~20 degrees inclusive, as lower than that on SG2/R2 stainless steel @ ~63-64 HRC won't hold up in this guys professional use.
The owner's rank in the commercial kitchen is Chef de Partie (just below head-Chef and sous-Chef) and he and his team are responsible for prep cutting all the meats, vegetables & patisserie ingredients.
He is one of the guys that provides me with detailed feedback on edge performance & edge longevity, which i then use to try to improve upon my edges.
Click to expand...
Was it a Tormek that you used to put the edge on?
 
kwackster said:
The edge angle i put on this Takamura measured ~20 degrees inclusive, as lower than that on SG2/R2 stainless steel @ ~63-64 HRC won't hold up in this guys professional use.
The owner's rank in the commercial kitchen is Chef de Partie (just below head-Chef and sous-Chef) and he and his team are responsible for prep cutting all the meats, vegetables & patisserie ingredients.
He is one of the guys that provides me with detailed feedback on edge performance & edge longevity, which i then use to try to improve upon my edges.
Click to expand...
Is "Inclusive" meaning total angle of BOTH sides. Meaning either 10deg each side or straight one side and 20 deg the other side?

I tried one side straight and one side narrow angle(no way to measure). It can get very sharp, BUT it is fragile, meaning it won't hold edge for very long and easy to be damage. Unless the knife is used only to cut soft meat etc., it can easily be damaged.

Are these mostly for show, not really practical everyday use?
 
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