How do you choose the best angle to sharpen an edge?

[Fred.Rowe]

When you are deciding what angle to use to sharpen a flat ground blade; what are the deciding factors?

After you select the angle, what datum or surface of the knife do you use to sharpen it. In other words, do you select ten degrees as your sharpening angle and then use the flat surface of the ricasso, or blade center line, to reference the ten degree grind or do you use the surface of the bevel as the point of reference to grind the edge?

This question does not apply to convex ground bevels or convex edges.

Fred

 

[BMK]

The link below will take you to a chart of cutting tool type and angles. You can extrapolate a lot of information off this simple chart if you think about the purpose and recommended angle of each tool. I only make knives with a single bevel to zero so my "datum" is the ricasso.

It's all about material separation.

http://www.surgisharp.com/index_files/Page522.htm

 

[richard j]

i tend to go off the flat surface of the ricasso or flat along the spine.

 

[Fred.Rowe]

Let me rephrase this question and post it later.

Fred