Wall anchors support picture frames, artwork, shelving, mirrors and other wall hangings when there is no framing stud available in a hollow wall. They are also necessary in certain solid walls, like plaster, brick and concrete, each using its own specific kind of anchor. There are three basic types: sleeve, toggle and expansion. The load hung on the wall anchor determines which one to use. Without proper anchoring, screws would tear out of the wall under the force of the weight they are meant to hold. There are numerous types within each category with specific limitations and advantages.
When sleeve anchors are driven into a wall, they are slightly undersized. Then, as a nail or screw is hammered or threaded into the anchor material, the expanding anchor tightens inside the wall. They are designed for light loads, up to 40-pounds in drywall and plaster when using the plastic conical and ribbed type or a metal winged type. There is also a heavy-duty lead sleeve and wood plug suitable for brick, stone and concrete, both of which will hold up to 125 pounds. These anchors are designed for lighter loads and therefore are not for use in ceilings.
These are best suited for hollow walls only, working equally well in a drywall situation or plaster. There are two kinds and they both operate by spring action. A screw drives apart a pair of plastic prongs, holding them firmly against the inside wall. The plastic toggle supports up to 40-pounds. And similarly, a winged toggle bolt spreads apart in the second type, holding up to 100-pounds from a vertical wall due to its more robust design. Unlike any of the sleeve types, a toggle bolt will hold weight even from a ceiling. They are ideal for hanging plants and ceiling lamps.
Expansion bolts hold the most weight. They work when a screw crimps the sides of a metal sheath, compressing them inside the wall. A hollow expansion bolt will hold up to 150-pounds in drywall and plaster. The other three types are for masonry, concrete and brick, also good for 150 pounds. Masonry wedges and sleeves are both similar to their drywall counterpart, but as the name implies, they are designed for stone and tile. A lag shield, however, is good for brick and concrete. Expansion anchors are for the heaviest of walls and therefore support the most weight.