sharpen fostner bits

[phil harold]

how do you shapen these drill bits

mine are getting dull and some have found hidden metal...

[Doug Garson]

Post your question on Youtube, plenty of how to videos on the subject. Here's one

https://www.youtube.com/watch?v=rLoEulA4mM8&t=336s

[Lee Schierer]

I use a small flat file on the cutting edges.

[Bradley Gray]

I use an auger bit file - they have "safe" corners

auger bit file.png

[Doug Hepler]

I use a diamond hone. I second the suggestion that you search on you-tube. The main thing is not to sharpen the outside because you will change the diameter. Sharpen the cutters inside the bit.

[phil harold]

Post your question on Youtube, plenty of how to videos on the subject. Here's one

https://www.youtube.com/watch?v=rLoEulA4mM8&t=336s

Facepalm
thanks for the redirection