The self-drilling anchor functions as a drill, drilling its own hole, and as an anchor, using the external plug provided. Self-drilling anchors can be used in stone or concrete and are suitable for hanging various pipes and lines, duct work, cable support racks and trays. The self-drill is also effective for fastening medium-weight equipment, control systems, and structural components. Self-drills are sold unassembled. After using anchor to drill hole, remove anchor. Clean hole and anchor, insert tapered plug into "tooth end" of anchor. Place anchor, plug down, into hole. Allow assembly to bottom out. Then hammer or drive anchor over expander plug and shear off top of anchor flush with base material. Anchor is now prepared to receive bolt.