What type of drill bit is used to drill a pearl? The pearls are half drilled, but have too shallow of holes for the post on the ring. I could shorten the post but it might make the piece not as durable as I would like.
Pearl reamers are designed for this very task. Diamond drill bits are also great for enlarging holes. When drilling bead holes, diamond wire can be inserted into a jeweler's saw and used similarly to a diamond drill bit in a bead reamer.