asymetric bevels

[Ken S]

I watched a video by Ken Schwartz where he reground a knife with 50/50 bevels (symmetrical) to 100/0, all the bevel being on one side. He was demonstrating how a knife could be ground with any combination from 100/0 to 0/100, grinding the bevel on the other side.

I know some Japanese knives are ground with only one bevel. My $12 Kitchenaid Santoku knife works very well at 50/50. I am left handed. I am thinking about purchasing another identical knife and grinding it 100/0 for my own use.

Ant thoughts?

Ken

[Lafontaine]

Hi Ken. I would be really interested in watching such a video...
Is there any link available ?

By the way i'm new here and with tormek machines and jig.

[Ken S]

Welcome to the forum, Lafontaine.

Here is a link I found discussing asymmetric bevels. The presenter actually uses a belt grinder, but a bevel is a bevel. As I encounter more vudeos on this dubjuct, I will post links.

https://m.youtube.com/watch?v=dDsWh_M7Rek&time_continue=34&ebc=ANyPxKrmG99Ee8qqMoHFV0JEJONUsu7ezj3jfyLLE9SVpMlmCBb3sEe0UB1Y612t3S7wiwA0QSmp

Ken

[bisonbladesharpening]

Japanese sashimi knives are only beveled on one side,
the back side is slightly hollowed out. Usually they are hand made and
hand sharpened by highly trained chefs.  Lots of interesting videos on the youtubes

[Herman Trivilino]

Japanese sashimi knives are only beveled on one side,
the back side is slightly hollowed out. Usually they are hand made and
hand sharpened by highly trained chefs.  Lots of interesting videos on the youtubes

If single-beveled knives are for slicing things like sashimi rolls, I can see how the hollowed back side would keep the slices from sticking to the blade. It would be an interesting project to try to grind an old kitchen knife with that profile and then experiment with how well it performs. It may be that such knives would perform well but I can see how they would be hard to market. After a few sharpenings the edge would get into the hollow and the knife would be at the end of its useful life.

[Ken S]

I have a knife on order for a rather low tech experiment. I ordered an identical knife to my Kitchenaid Santoku. I will leave the original with the 50-50 dual bevel. I will convert the second knife to left bevel only. (I am left handed.) I cut cheese often. I will see if the single bevel cuts any differently. I will post results.

Ken

[Ken S]

My duplicate Kitchenaid Santoku knife arrived yesterday. I resharpened it to single bevel this afternoon. I happened to use my T7 with the SG-250, beginning with the grinding wheel graded coarse. After the grinding was complete, I tried a new (to me) technique. I used the stone grader with a light touch to regrade the grinding wheel to approximately 600. I made several passes and then regraded the grinding wheel to full fine. (I will discuss this more in a new topic in Tormek General.) Last operation was the leather honing wheel.

I raised a good burr over almost all of the blade. For some unknown reason, I was unable to raise a burr at the 3/4" of the knife at the tip, even with considerable extra grinding.

How does the reconfigured knife work? One thing is certain; the single bevel (designed for left handed use) works terribly as a right handed knife. It seems to work somewhat better than the double bevel knife in left handed use. As a lefty, that was my goal. I will not pronounce any success until I have used it for a while.

I am also not sure of the most practical bevel angle. Presently, the single bevel is 15°. That may prove too acute; time will tell.

Back to work......... Comments welcome.

Ken

[Herman Trivilino]

For some unknown reason, I was unable to raise a burr at the 3/4" of the knife at the tip, even with considerable extra grinding.

This is where a magnifier with good light comes in handy. Or better yet a low-powered scope. There has to be a reason why you weren't able to grind all the way to the edge. Either that, or the burr was so fine it missed detection.

[Ken S]

Herman,

The tip situation is puzzling. Logic tells me the tip area should sharpen like the rest of the edge. I did not notice anything whwn I have sharpened the supposedly identical knife (with the original double bevel profile).As I recall, I actually sharpened that knife with the 180 grit CBN wheel followed by the leather honing wheel.

In hindsight, perhaps I should have ground away the original two bevels by setting my Herman jig square and then grinding the single bevel.

The next time I sharpen the single bevel knife, I will change the bevel angle to 20°. With the double bevel knife, the bevel angles are each 15°, giving an edge angle of 30°. With the single bevel configuration, the 15° bevel angle is also the 15° edge angle. That may be too steep for this garden variety knife.

Getting beyond my foolish sharpening vanity, I use this knife for slicing. I do not ever recall cutting with the tip of the santoku knife. For my use, a blunt tip would work just as well. My cutting board is next to my knife block. A sharp tipped knife is only two seconds away. And, as I am the only user (my wife is right handed), I have no customer complaints except curiosity with the dull tip.

I should run some BESS tests and quantify the sharpness difference.

Ken