The phrase “half-drilled” usually refers to pearls. Half-drilled just means that the item is partially drilled. It does not mean that it’s drilled exactly halfway through. The item is usually drilled just enough or part of the way through for the length of a post to be inserted. If you find that your post is too long, you can always trim a little off until it fits into the drilled space. Once inserted onto a post setting, half-drilled beads create a professional and polished look in your jewelry designs, as there is no visible stringing hole.