Drywall anchor

What is a drywall anchor?

A drywall anchor is a fastener designed to hold a screw securely in drywall (also called gypsum board) where there isn’t a wood stud behind the surface. Because drywall is relatively soft and hollow, a screw alone can tear out under load. Anchors solve that by expanding, threading, or toggling behind the wall to spread the force over a larger area.

How drywall anchors work

Drywall anchors increase holding strength in two main ways:

• Expansion or toggling: Some anchors expand behind the wall as the screw is tightened, creating a clamp-like hold. Others swing open a “toggle” that braces against the back of the drywall.
• Thread engagement: Threaded anchors cut or bite into the drywall, distributing weight along deep, coarse threads rather than relying on the paper face alone.

The result is a stronger connection that resists pull-out and reduces the chance of damaging the wall surface.

Common uses and applications

Use drywall anchors whenever you need to mount light to moderate loads to drywall and can’t hit a stud. Typical projects include:

• Picture frames and wall art
• Small shelves and display ledges
• Bathroom accessories (towel bars, toilet paper holders)
• Curtain rod brackets and blind brackets
• Hooks for coats, keys, or bags
• Light mirrors and décor

For heavy or dynamic loads—like TV mounts, wall cabinets, heavy mirrors, or anything that gets yanked or leaned on—anchor into wood studs whenever possible. Anchors can assist, but the primary support should come from studs for these items.

Types of drywall anchors

Drywall anchors come in several styles, each with different strengths and installation steps. Always check the packaging for weight ratings and drywall thickness compatibility.

• Plastic expansion anchors (ribbed plugs):

  • How they work: Inserted in a predrilled hole; the screw expands the plastic to grip the drywall.
  • Typical use: Light loads (often around 10–20 lb in 1/2 in drywall). Great for small frames and hooks.
  • Pros: Inexpensive, simple.
  • Cons: Low capacity; can loosen in soft or damaged drywall.

• Self-drilling (threaded) anchors — plastic or metal:

  • How they work: The anchor has coarse threads and a sharp tip. You twist it directly into the drywall, then drive a screw into the center.
  • Typical use: Light to medium loads (commonly 25–50+ lb depending on material and thickness).
  • Pros: No pilot hole needed, quick install, good all-around option.
  • Cons: Can strip if overtightened. Metal versions hold more than plastic.

• Molly bolts (hollow wall anchors):

  • How they work: A metal sleeve expands behind the wall as the screw is tightened, forming a wide footprint.
  • Typical use: Medium loads (often 25–75 lb). Good for items you might remove and reinstall; the sleeve stays in the wall.
  • Pros: Reliable, spreads load well.
  • Cons: Requires correct hole size; a bit more involved to install.

• Toggle bolts (spring toggle) and strap toggles:

  • How they work: A hinged or strap-connected toggle passes through a hole and flips open behind the wall, bracing against the backside.
  • Typical use: Medium to heavy loads (commonly 50–100+ lb per anchor in 1/2 in drywall; some strap toggles are rated higher).
  • Pros: Very strong in shear if properly installed.
  • Cons: Requires a larger hole; once removed, the spring toggle falls inside the wall. Not ideal for repeated removal.

Note: Ratings vary by brand, drywall thickness (3/8 in, 1/2 in, 5/8 in), and installation quality. Always use the manufacturer’s guidance.

Choosing the right anchor

Consider these factors before you start:

• Weight and load type:
  • Light décor (under ~15 lb): plastic expansion or plastic self-drilling anchors.
  • Medium loads (~15–50 lb): metal self-drilling anchors or molly bolts.
  • Heavier loads (50+ lb) or brackets with leverage: toggle bolts, or better yet, fasten into studs.
• Drywall thickness and condition: Thicker, sound drywall holds better. Crumbly or previously patched areas reduce capacity.
• Number of anchors: Using two or more anchors spreads the load. The safe capacity is not always perfectly additive, but it helps.
• Orientation and leverage: Shelves and cantilevered brackets create torque. Choose stronger anchors or hit at least one stud.
• Wall type: For plaster-and-lath or tile over drywall, use anchors rated for those materials or a different fastening strategy.

Installation basics by type

Always mark level locations, check for studs, and avoid wires and pipes.

• Plastic expansion anchor:

  1. Drill a pilot hole to the size specified on the package.
  2. Tap the anchor flush with a hammer.
  3. Drive the screw through your fixture into the anchor. Stop when snug; don’t crush the drywall.

• Self-drilling (threaded) anchor:

  1. Use a screwdriver or driver bit to turn the anchor clockwise until the flange is flush with the wall.
  2. Position your fixture and drive the included screw. If it spins, back it out slightly; don’t overtighten.

• Molly bolt:

  1. Drill the recommended hole.
  2. Insert the molly and tap flush.
  3. Pre-expand slightly by tightening the screw until the sleeve grips, then remove the screw.
  4. Mount your fixture and reinstall the screw until snug.

• Toggle bolt / strap toggle:

  1. Drill the larger hole size listed on the packaging.
  2. Assemble the toggle on the screw through your fixture bracket.
  3. Push the toggle through, pull gently to seat it, and tighten while keeping tension so the toggle stays flat against the back of the drywall.

Tip: For neat holes, use a sharp bit and keep the drill level. A hand screwdriver gives better feel and reduces overdriving.

Maintenance and removal

• Periodic checks: For items used daily (like towel bars), re-snug the screws if they loosen.
• Removal: Back out the screw. For mollys, you can collapse the sleeve by pushing the flange into the wall and patching. For toggles, the backer will fall into the cavity. Patch the hole with joint compound if you relocate hardware.
• Reuse: Most anchors are not designed for reuse in the same hole. If a hole becomes enlarged, patch and redrill nearby.

Common mistakes to avoid

• Using a light-duty anchor for a heavy or leveraged load.
• Overtightening, which strips the anchor or crushes the drywall face.
• Installing in damaged, damp, or crumbly drywall.
• Relying on anchors for ceiling loads; only use overhead-rated toggles and never for fans, swings, or gym equipment—anchor to framing instead.
• Skipping a stud search. Often one bracket can land on a stud for a stronger install.

Safety checks

• Use a stud finder and a live-wire detector before drilling.
• Know what’s behind the wall near plumbing fixtures and switches.
• When in doubt, step up to a stronger anchor or move the mounting point to a stud.

Related terms

• Stud: The vertical wood or metal framing behind drywall.
• Stud finder: A tool that locates studs and sometimes live wires.
• Pilot hole: A predrilled hole that guides an anchor or screw.
• Toggle bolt: A specific type of drywall anchor with a spring or strap toggle.
• Masonry anchor: A different class of anchors for brick, block, or concrete walls.

Practical examples

• Hanging a 12 lb frame: Two plastic self-drilling anchors rated 25 lb each in 1/2 in drywall provide a comfortable margin.
• Mounting a 30 lb mirror: Use two strap toggles rated for at least 50 lb each, or place at least one screw into a stud.
• Installing a towel bar: Metal self-drilling anchors hold up better to daily use. If one bracket can hit a stud, do it.
• Curtain rod brackets: These see leverage. Aim for studs; if not possible, use metal self-drilling anchors or toggles and at least two fasteners per bracket.

With the right anchor, accurate placement, and careful tightening, you can get strong, reliable mounts on drywall without hunting for a stud every time.