dust corner dust corner dust corners are triangle-shaped pieces, usually made of brass or nickel, that are used to prevent dust from accumulating in corners. stair dust corners are used on staircases at the point where the tread, riser, and stringer meet. dust corners make household chores such as sweeping and vacuuming more convenient. stair dust corners originated during the victorian era. dust corners typically have a small hole in the middle so a nail can be hammered into the stairs.