full convex zero grind vs flat grind with convexed edge....please help

[boki_zca]

Is there any difference in performance between two...........and how significant the difference is.........Any advantages of one over other.......thx

 

[Obsessed with Edges]

Some of the resistance to cutting is from the 'shoulders' of the edge bevel. Generally speaking, I've noticed continuing improvement in slicing performance, as the comparison progressed from a flat grind with a secondary V-bevel, to a flat grind with a convexed edge, then to a full convex with a zero edge (I spoke to this latter type in your other thread, re: Opinel's full convex). It seems to me, the less pronounced the 'shoulders' of the edge bevel are, the easier the blade will glide through the media being cut.

Can't say much as to which type is more durable (if any). Other variables, like steel, hardness & heat treat, and blade/edge thickness play into that.

 

[foxx]

Full convex blades have a continuous curve to the geometry. This allows the material being cut to flow smoothly up the walls.

 

[cziv]

Is it just me? I've run my thumb lightly "across" a fully covexed blade and it didn't catch or feel as sharp as a well done V grind bevel.

 

[Obsessed with Edges]

So far as the very edge itself is concerned, I have found it simpler to create a shaving/hair-whittling edge with a true V-bevel. That's what's in play when testing on a fingernail (or the 'bite' felt, when lightly running the edge across the skin). But, in terms of how the blade performs after the edge has made the initial cut through the surface of thicker material, the grind of the blade as a whole comes more into play. That's where the full convex really excels. I'm willing to trade off a tiny bit of the shaving sharpness, for the true effortless slicing afforded by a smooth convex grind. In real-world use (anything other than whittling hair), it makes for a very, very useful cutter.

And I've found, the more I practice at it, I'm getting closer to achieving the 'hair-whittling' capability with the convex edges. If done correctly, even a fully convexed blade will still have what amounts to a sharp 'V' at the very edge. Anything 'round' just wouldn't be quite as sharp.

 

[db]

Alot will depend on how thick the blade is. A very thin flat grind with a very shallow convex edge will cut better than a thick fat convex full grind. Also a thin shallow full convex will out cut a thick flat grind with a thick edge. I personally like a shallow thin convex edge on any type of blade grind. Most of my knives are almost a full convex just because I like a very thin convex edge.

 

[cziv]

So far as the very edge itself is concerned, I have found it simpler to create a shaving/hair-whittling edge with a true V-bevel. That's what's in play when testing on a fingernail (or the 'bite' felt, when lightly running the edge across the skin). But, in terms of how the blade performs after the edge has made the initial cut through the surface of thicker material, the grind of the blade as a whole comes more into play. That's where the full convex really excels. I'm willing to trade off a tiny bit of the shaving sharpness, for the true effortless slicing afforded by a smooth convex grind. In real-world use (anything other than whittling hair), it makes for a very, very useful cutter.

And I've found, the more I practice at it, I'm getting closer to achieving the 'hair-whittling' capability with the convex edges. If done correctly, even a fully convexed blade will still have what amounts to a sharp 'V' at the very edge. Anything 'round' just wouldn't be quite as sharp.

Thanks, that's a good explanation! :thumbup: