DIYbanter - View Single Post - Back bevel works well (and two questions)

s wrote:

On Tue, 04 Oct 2005 17:02:06 GMT, "BillyBob"
wrote:

"George" George@least wrote in message
...

It affects clearance angle, which can increase the sharpness angle while
making the edge more durable. See Hoadly on sharpness.

How does it make the edge more durable? It seems to me that it makes the
cutting edge thinner, which results in an edge that will dull quicker.
Since its a bevel up plane, the angle of cut remains the same and the back
bevel just removes more metal behind the cutting edge.

Bob

back beveling a bevel up plane makes the edge thicker.

that is if you define the back as the side of the blade without a
bevel. if you define the back as the side away from the wood, then a
*front* bevel would make the edge thicker.

regardless of that bit of obfuscation, any secondary bevel, front back
or inside out will make the edge thicker. that's all fine and good
until the angle of the bevel against the wood exceeds the angle of
attack- or as someone else moer clearly just called it, the clearance
angle. when that happens the plane ceases to cut.
I never thought of it that way. I drew a couple pictures real quick, as
I read your statement. I agree. seems counter-intuitive, doesn't it??

Dave