Sal, why is the Delica ground so thick behind the edge ?

[Sjucaveman]

Here ya go. I guess take it up with Spyderco, maybe they don't know what they're talking about :rolleyes:

That's correct. They don't. False advertising pisses me off. This is pointless. I'm bowing out again. Back in another six months or so ... maybe

It seems your understanding of zero grind is incorrect.

[Sumdumguy]

The only stone I'll throw is at the title of this thread

[guywithopinion]

I'm not an edge nut exactly. However, the basic geometry could go something like this. Say you start out with 2.5mm by I dunno, 25mm blade stock. A full flat grind simply means the primary grind goes the whole way down the blade stock at a consistent angle. If you made two knives, you could grind one where it is 2.5mm on the spine side, and is only 0.5mm on the edge side. You could grind the other where it is 2.5mm on the spine side and is 1.5mm on the edge side. Then you take both and put a 17 degree per side secondary bevel (the actual edge) on both. Both knives are the same size, both FFG from 2.5mm stock, both have a 17-degree edge on them. But one will be much thicker behind the edge. And the secondary bevel on one will look much wider than the other, in spite of being at the same angle.

I'd also point out that you could have say 2.5mm by 50mm stock (i.e. the blade will be wider from edge to spine). Perhaps you grind that at the same angle as the previous example that ends up being 1.5mm. Now it will only be 0.5mm at the edge, exactly the same thickness at the edge as the previous more acute knife. Except they have very different blade design. (I am not qualified to say which will cut better, etc).

Here is a picture of the first scenario I was describing. Both starting stock are the same. The blue lines are the full flat grind lines, and the red lines are the secondary grind to form the cutting edge. The red lines are at the same angle in both.



The dashed grey line across the image is just to point out where the "behind the edge" line is on each, and where it lines up with on the other, to help illustrate how two FFG knives from the same stock with the same edge angle can be different behind the edge.