How close to the choil area on blade should it be sharpened?

[Redsnake1997]

What do you all prefer. Hopefully I'm describing this the correct way. I have several custom knives and I've noticed that some do, some don't... have the blade sharp up close to the handle on the choil area.

Here's a pic of where I'm referring too... this blade doesn't seem to be sharp all the way up

What do you prefer? I prefer to have the choil area sharp all the way back... but a lot of customs i have are not sharp... say 1/4" or so along this part of the blade.

Is there a reason why (perhaps in the blade grinding phase) that I don't know about that would cause this?

I'm not criticizing... just want to be educated.

Thx!

 

[zerogee]

Grinding the underside of the ricasso a little too far forward and getting into the area of the plunge cut can extend the unsharpened area more than it should be. But typically the length of the unsharpened area is dependent on the "corner" radius of the plunge cut -- if a sharper transition is used, the unsharpened area is shorter -- if a more gradual radius is used, the area is longer. If you're having trouble visualizing this, think of a plunge cut with a 90 degree angle (no corner radius on the plunge cut) -- you would have no unsharpened area back to the ricasso. Note that a more gradual radius on the plunge cut will give a stronger blade.

 

[Redsnake1997]

Thanks for the reply. This helps me to understand how the differences in grinds effect that 'area' around the ricasso a lot better.

 

[argel55]

Another factor also in the way it sharpens is that the belt you sharpen with is taut but not totally flat. It is flexible on the edge so it tend to curl a little bit in this area. The knife was sharpened on a 240 grit then a 15 micron belt, and then buffed.