Molly (fastener)

A molly or molly bolt, often misspelled moly, is a formerly trademarked name for a specialized screw fastener used with drywall, as a hollow-wall anchor. Larger sizes permit reasonably heavy objects, such as shelving, flatscreen-TV mounts or central-heating radiators to be attached to drywall in locations where there is no stud behind the drywall. For heavy objects, multiple molly bolts may be required.

The fastener is an anchor, an expandable sleeve that slides into a hole drilled into the wall. A lip wider than the hole prevents it from falling behind the wall. A machine screw is then screwed into the sleeve, causing the anchor to bend, expand, spread and grip against the inside of the drywall.

Mollies come in various diameters and "grip lengths" for different drywall thicknesses and to support different loads.

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