I have been using a flex shaft and small drill bit (#60) to drill
holes in 20 g copper. It seems to take forever to get through the
metal on most occasions.
High quality drill bits generally will give better results. Be sure
you’re getting good high speed steel bits, and preferably, from a
major manufacturer. I bought some once on ebay that seemed a great
deal. Good steel, but not a good grind nor well sharpened. Worthless
drills for a bargain price aren’t a bargain. So anyway. Get high
quality drill bits and you’ll see much faster drilling.
Also, be sure to use a lubricant of some sort. Bur life, bees wax,
ordinary machine oil, or even saliva will all not only help to keep
the bit cool, but will speed up the cutting markedly.
Dinging the metal first may not be quite enough to give the bit a
good start. Use a center punch, which puts an actually conical
depression in the metal. Gives a solidly located hole since the bit
will be less likely to wander around a bit before biting into the
If, while drilling, the “feel” changes, seeing coarser or the bit
seems to be slowing down, pull it back slightly to allow more lube to
get into the hole before resuming. This also allows the chip to break
free, and the hole to clear out a bit before you continue, again
helping the lubricant to get into the hole.
If the drill bit heats up and discolors during use, you’re either
not using lube, or more likely the drill is dull and needs
resharpening or replacing.
I’d expect that your holes might take somewhere in the area of ten
seconds each, to drill, if all the above are done.