Drills vs End Mils

[Mitch Alsup]

I wouldn't use an end mill to make a hole on the lathe for the same reason that I wouldn't use one on a drill press.. Unless the end mill is perfectly centered the flat end will cause the end mill to walk on the work. A drill bit with a 118º angle has a tendency to self center

to some extent

on the rotating work even if the drill is slightly off the spindle axis. If I needed a flat bottomed hole, I would first drill a slightly undersized hole then carefully start an end mill to finish the hole to size and cut the flat.

 

[P. Waller]

I mostly use DHMO for drilling, turning and milling. It can be fatally toxic given the correct circumstances however so be wary when using it, in moderation it is harmless. Be aware that it causes corrosion so is not suitable for hobbyists in all applications., it is mostly used in production equipment.