Expanding Anchor for 10" (254 mm) Hole used with 0.75" (19.1 mm) Diameter Rod. Chance "Bust" Expanding Anchors expand to take full advantage of the eight blade wedges to expand into undisturbed soil. Hot dipped galvanized per ASTM A153. Nut retainer on bottom of anchor holds nut in place during installation. The effectiveness of the anchor is dependent upon proper size hole and the thoroughness of backfill tamping.