steels and angles? how fine?

[cschol]

I have massed a few dozen fixed blades now and an equal amount of folders of various steels, grinds and values. Along with the blades and axes too I have 3 diamond plates a cheap combo stone. Handful of strops of varying compounds. A Work sharp original.
I can sharpen most blades to shave and cut phone book paper free hand.
Maybe I missed the thread or the experts can way in here.
Is there a source for minimum angles for certain steel and how fine can a steel be honed and polished and still be effective.
For example: I have a Buck Vantage in S30v that came very sharp but the typical factory finish, rough and uneven. So how much can I reduce the final edge angle and how fine can it be polished before the carbides get in the way. How about a blade in 440c or D2. I know that it depends on how I plan to use it but I'm curious how far can a certain steel be taken.
Is there a resource that addresses this?

 

[me2]

You probably won't find such a guide, as steels vary from one maker to another enough that it wouldn't hold. The general notion is to sharpen as low as you can until you see damage from use, then back up just a bit so the damage stops.

 

[drail]

If you go very thin you'll have chipping and rolling when you do anything tougher than slicing a potato. You want some thicker metal backing up that thin edge. You must find the perfect compromise between razor thin and thick enough to take a load. Don't worry - you'll find it. Just keep trying slightly different angles.

 

[cschol]

Thanks guys
I was looking for a short cut. Probably won't be to fulfilling if I cheat it.
Started with a Becker BK15 at 20-22 inclusive just to see how it goes.

 

[Fred.Rowe]

One rule of thumb. If the main bevels are taken close to zero above the edge, a more obtuse sharpening angle can be used. The thicker the shoulders directly above the cutting edge the more acute the angle can be. Or the thicker the more acute, the thinner the more obtuse. Its a decent way to access an effective sharpening angle.

The steel itself is another aspect of selection, as well as the actual hardness. It would be nice if we knew the heat treat technique and temperatures as well, these of course are not usually available unless the knife is a hand made item where this can be discussed with the maker. I do give this information to the buyers of my knives along with the edge angle the knife was originally sharpened, along with a degree wedge that matches the sharpening angle.
In a perfect world this information would be available to all knife buyers when the knife is purchased.

Regard, Fred

 

[Gaston444]

I have found thicker edges at a lower angle suffer more damage while chopping wood than thinner edges at the same low angle.

The reason, I suspect, for that observation that thinner edges are tougher in wood, is that thicker edges decelerate more brutally in wood, even at thin angles, and this induces more yaw as the edge penetrates the wood, leading to stress on the edge apex. Thinner edges decelerate straighter, and also more softly, so they appear more damage-proof.

An ideal edge for a big chopping knife, to me, is a hollow grind with a 0.020" edge at the shoulders, with a 12-13 degree per side edge. Steel ideally should be D-2, Aus-6/8 or 440B/C. I found many high tech steels to be inferior for chopping, among others S30V, as were many 440C blades, since this steel is unforgiving to heat-treat right... Thicker edges were always more fragile on wood due to the lower lateral stability on impact (in Maple).

Gaston