Best way to make burrs fit latch style dental drill?

[cumminskta]

Hi everyone,

My searches didn’t come up with any specifics unfortunately.

Can anyone point me in the direction how to best make notches on the 3mm burrs that will allow them to fit into the latching system on an angled dental hand piece?

I was able to get a section flattened with a hand file, I just can’t get accurate notches and the burrs are too small for my lathe to try to cut a section

Thanks!