Microbevel grind type different than primary bevel?

V

VermontMaple

Joined
May 29, 2021
Messages
3
Hi,

So from my understanding there is concave(rounded in) flat/straight and convex(rounded out) grind types. My question is can a blade have a flat primary bevel and concave secondary bevel for example or other difference between primary and secondary grinds?
 
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VermontMaple said:
My question is can a blade have a flat primary bevel and concave secondary bevel for example or other difference between primary and secondary grinds?
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Yes, of course.

If you strop a lot, you will end up with a convex secondary edge.

While a concave (more commonly known as a hollow grind) secondary edge isn't that common on a full flat primary, it is possible. It makes for a very fragile, thin edge in most cases, unless the blade stock is pretty thick to start with.

Note you said "concave" twice in your original post, but indicated two different profiles. I am sure you meant CONVEX (rounded out), the second time.

Welcome to the forum.
 
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shane45-1911 said:
Note you said "concave" twice in your original post, but indicated two different profiles. I am sure you meant CONVEX (rounded out), the second time.
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Yes I did mean convex the second time around. Thank you. And thanks for the reply. It would seem to me the secondary edge being so small usually, would mean its subject to change based on the sharpening style of the user?
 
The blade on the Sebenza is hollow grind and the edge is micro-convex for example.
 
While we're on terminology...it is my understanding that a microbevel is a tiny little additional - tertiary, if you will - bevel on the edge bevel. I.e. a blade potentially has a primary bevel (flat, hollow or convex), a secondary bevel (the cutting edge), and a tertiary microbevel, which is usually applied at a larger inclusive angle to stabilize a cutting edge with a relatively small inclusive angle.

Addendum: A microbevel can also be a tiny V-bevel on a convex or scandi grind, both of which ideally have no secondary bevel at all but are ground "to zero". Often such is criticized when on a factory edge.
 
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Bottom line: So long as the apex is keen & sharp, it doesn't particularly matter what shape the edge takes in sharpening, whether it's a V-bevel, convex or hollow (concave).

As mentioned, all freehand edges will have some convex. This especially includes any edge stropped with compound on a substrate with any softness or give to it - even if the held angle is perfectly steady. It happens because the substrate of the strop will conform or 'roll' around the edge under any pressure. But so long as the convexing happens just behind the apex, and not at the apex itself, the edge can still be maintained sharp. Keeping the convex behind the apex is all about maintaining a stropping angle that's conservatively lower than the actual edge angle. So, any contact with the edge will be the lightest possible 'skimming' of the very cheeks of the apex, without letting the apex itself roll into the strop substrate. It becomes less of a concern if the strop substrate is much firmer, like hardwood instead of leather.
 
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Ha, I just saw there's a sticky thread on microbevels up top! Could've saved me some typing...
 
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