Blade width to edge angle

[williamsld8]

I have noticed recently that when sharpening my knives with thinner blades, I have more difficulty getting an edge angle that will easily shave/hair whittle, as opposed to wider blades, that I can quickly and easily get these results with. For example, two blades that measure approximately .34 inches wide were honed to a very shallow angle (not an absolute shallow angle, but shallow in relative terms to how close the spine was to the stone), and doesn't perform as well as a few blades that measure from .62 inches to .75 inches sharpened to the same "spine relative" angle. Is this the way blade geometry normally plays into sharpening and performance? I deduct that the wider blade sharpened with the spine the same height from the stone would end up with a much steeper angle than the more narrow blade, but correct me if I'm wrong.

 

[Obsessed with Edges]

I do think it's much harder to hold a precise angle with a very small blade, assuming freehanding. The blade width (edge to spine) is the 'hypotenuse' of the right triangle, with the height of the spine above the hone being the 'Y' axis (vertical). With a very small (narrow) blade, just a tiny variation in the 'Y' (height above the hone) will produce a more drastic change (percentage-wise) in the angle. If one were to make the same absolute change in the 'Y' (height above the hone), with a blade that's significantly wider, edge to spine (much longer hypotenuse), the relative (percentage) change in the angle will be much less. I think that's why it's easier to keep the angle relatively consistent with a wider blade. Chances are, the height of the spine above the hone is still a bit shaky, but the impact of it, on the edge angle, is less significant than with a narrower blade.

All logic aside, I've also sometimes found small knives (presumably with smaller handles) a little tougher to hold comfortably, when sharpening. I just have to believe that's impacted the quality of the finished result. For a long time, I really began to believe small blades wouldn't take 'good' edges. Until, that is, I finally put one of them in a guided system's clamp. Then, like magic, it shaves! That was the not-so-subtle clue that I needed to work on my technique and steady my hand a bit more.

 

[willis]

A 20(or 15 or whatever angle you are using)degree angle is a 20 degree angle irrespective of the measurement of the blade from edge to spine.The wider blades spine will be farther from the stone than the thinner blades if both are at the same angle.

Davids post was not up when I posted.He said it much better than i did.

 

[pwet]

agreed, and none are easier to hold at a steady hand, if your hand shakes it will shake the same with a narrow or a wider blade it doesn't make any sense. the spine on the narrower blade will be closer to the hone but the angle will be the same.