Wall anchor

A wall anchor is a fastener that expands, toggles, or grips inside drywall to hold a screw in place when there is no stud directly behind the mounting point. Common types include plastic expansion anchors, self-drilling threaded anchors, and toggle bolts, and each has its own weight rating that is almost always lower than what the same screw could hold if driven directly into a stud.

Anchors are useful for lightweight items or for a secondary mounting point on something that is already partly anchored into a stud, but they are not a substitute for framing when hanging genuinely heavy storage like a loaded shelf or a bike rack. Even a well-rated anchor is limited by the strength of the surrounding drywall, which can crumble or pull out under sustained or shock loads.

A common mistake is treating anchor weight ratings as interchangeable with stud-mounted weight ratings, or using a light-duty plastic anchor for something that clearly needs a heavier toggle bolt or, better, a stud. When in doubt, shifting a shelf or bracket a couple of inches to land on a stud is almost always the more reliable choice over relying on an anchor alone.