expansion bolt


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expansion bolt

[ik′span·shən ‚bōlt]
(design engineering)
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.

expansion bolt

expansion bolts
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.
References in periodicals archive ?
Expansion bolts (also called molly bolts) are similar to anchors, except that once the screw is run through the anchor unit, the unit expands behind the wall, creating a true anchor that won't allow the screw to be pulled out by the weight of the item.
The heavy cardboard casting tube (a form for pouring concrete columns) was wrapped in thin galvanized sheet metal; expansion bolts secure the vertical seam on the back.
Using the longer nails, anchor the two back wall supports to studs (if the small end supports don't span two studs, you may need expansion bolts to secure them).
Woodscrews attach the central piece to a wall stud; expansion bolts secure branches to the gypsum board wall.
When plants reach full bloom, in early July, they are secured to the wall with clips and expansion bolts (see photograph at bottom right).
(Sockets may require expansion bolts instead of the screws supplied.)