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expansion bolt[ik′span·shən ‚bōlt]
A bolt having an end which, when embedded into masonry or concrete, expands under a pull on the bolt, thereby providing anchorage.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
An anchoring device having an expandable socket that swells as a bolt is tightened into it; used in masonry walls for attaching timber, etc.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.