Drywall anchor

A drywall anchor is a fastener designed to hold screws in hollow drywall walls where there is no solid framing behind the surface. The anchor expands inside or behind the drywall, distributing the screw’s load over a larger area to prevent it from pulling out.

Common types

• Plastic expansion anchor: A ribbed plastic sleeve that you tap into a pre-drilled hole. When you drive the screw, the sleeve expands against the sides of the hole. The simplest and cheapest option, suitable for light loads (10–20 pounds).
• Self-drilling anchor (E-Z Ancor): Has a large, coarse thread that screws directly into drywall without a pilot hole. The wide threads grip the gypsum core. Good for moderate loads (30–50 pounds).
• Toggle bolt: Spring-loaded wings that open behind the wall, distributing load over a wide area. The strongest drywall-only anchor — can hold 50–80 pounds or more.
• Hollow-wall anchor (molly bolt): A metal sleeve that expands behind the wall as the screw is tightened. Stronger than plastic anchors and reusable in some cases.
• Threaded drywall anchor: A metal or plastic insert with machine-screw threads inside. You screw the anchor into the wall, then drive a machine screw into it. Provides a more secure hold than plastic expansion anchors.

When to use them

Drywall anchors are used whenever you need to mount something to a hollow wall and cannot (or choose not to) locate a stud. Picture frames, towel bars, light shelving, and curtain rods are typical applications. For heavy loads — bookshelves, TV mounts, grab bars — always locate a stud or use toggle bolts.

Why not just use a screw?

A screw driven directly into drywall has almost no holding power — the gypsum core is soft and crumbly, and the screw will pull out under even modest loads. Anchors solve this by expanding the contact area and distributing the force.

Matching the anchor to the load

Home improvement guides, including Lowe’s and Bob Vila’s, converge on the same weight ladder:

Load	Anchor type
Under ~20 lbs	Plastic expansion anchor
~30–50 lbs	Self-drilling / threaded anchor
~50–75 lbs	Molly (hollow-wall) bolt
75+ lbs	Toggle bolt

Two caveats matter more than the numbers. First, every rating assumes the anchor is installed exactly as specified — hole size especially; an oversized hole can halve the holding power of a plastic anchor. Second, weight ratings are for static loads with sensible safety margins: a shelf that gets leaned on, yanked, or loaded with books needs the next anchor up, or a stud.

The stud comes first

An anchor is the answer to “there is no stud here” — but checking for the stud comes before choosing one. Knock across the wall (hollow = cavity, solid thud = framing) or use a magnet to find the drywall screws that mark the studs. A screw into a stud holds more than any anchor in drywall, so the real sequence is: stud if possible, toggle bolt if not, and only a plastic expansion anchor for genuinely light loads.