Does a 2" (5 cm) cutting depth 1/16" (1.6 mm) drill bit even exist? If not, is there any way for me to make this hole? I'm drilling a fiberglass/foam sandwich if it matters, and I want to make a hundred holes. My cheap standard drill bits cut the fiberglass just fine, but are half the length I need. And yes, I'm aware that the reason they're kept short is so they don't break all the time.
This probably sounds weird – it's for installing a starlight ceiling effect in a fiberglass float tank.
Best Answer
A quick visit to a metalworking supplier website finds 3" long (overall length) ones with 1.7" cutting depth (presumably the flute depth, so for light-duty drilling if you "peck" (pull out to clear chips) when you get deep you could probably get it done. "Extended-Reach Drill Bits" A more extensive search might find a longer one. Buy them by the dozen, you probably will break some and they are usually cheaper that way.
A different metalworking supplier website has 6" and 12" OAL listed (under "aircraft drills" which the other site calls "Short-Flute Extended-Reach Drill Bits") but only 7/8" flutes, which would be a lot more pecking to get the chips out.