Martin Eastburn wrote:

That conical shape won't work very well, but they have
another cut that will.

I've recovered a broken 3/4" drill I got for free.
I first turned it like that and then cut the cross point.
Another one, I corrected to that form and then hand ground
the flats on it.

What is the other

They are the same 1/2 inch drill bit, with different lighting
Number 2 is after another grinding.

http://www.flickr.com/photos/27532210@N04/

I might try sanding the cutting edge with a rotary tool. That
would be my first use of a rotary tool sanding paper disk.










- cross point ? something like that.

Martin

On 5/7/2012 8:54 PM, John Doe wrote:
http://www.flickr.com/photos/27532210@N04/

A bit after sharpening.