Carbides

[basjoo]

Have read several interesting posts about carbide sizes of different steels and the associated problem of over thinning an edge while sharpening and tearing the carbides out in the process. I've also read about how acute an edge angle one can put on steels like vg-10 and s30v. Anybody know what the skinny is on this issue? Is this more about the grit size of the stone one is sharpening with or is it the edge angle one is using? thanx

 

[Cliff Stamp]

As you lower the sharpening angle and decrease the size of the abrasive, a point can be passed where the edge can't hold and cracks. For most people this will never be a problem because the angles it requires are extremely low.

I have only seen it happen consistently when edges are very thin either due to a high flat or hollow grind, and the angles are significantly under 10 degrees per side with *no* micro bevel. If you check under mag you will see the edge actually fragmenting.

In general, there is also another problem for people with *really* high standards for sharpness, I don't mean the ability to slice paper or shave, I mean people who will push blades into and past the region of shaving hair above the skin.

For those people like Jeff Clark, steels with fine grains and small well dispersed carbides will get sharper, but again you need really high standards and a lot of skill to be able to make this distinction.

-Cliff