In this guide, we will cover how butterfly anchors work, when to use them, installation steps, and tips for success, helping you achieve secure and lasting results in your DIY projects.
What Is a Butterfly Anchor?
A butterfly anchor usually means a toggle bolt. It’s a fastener made to hold heavy items on hollow walls like drywall and plaster.
It has spring-loaded metal “wings” that fold flat when you push it through a hole, then pop open inside the wall.
Important Clarification:
- Toggle Bolts = Spring-loaded wing anchors (commonly called butterfly anchors).
- Molly Bolts = Metal sleeves that expand when tightened (different system).
- Butterfly anchor is a casual name for toggle bolts. It is not the same as a molly bolt.
Why Use a Butterfly Anchor?
Hollow walls are weak for standard screws. Butterfly anchors spread the holding force over a wide area behind the wall, providing a secure and lasting grip, perfect for medium-to-heavy loads.
Benefits of Butterfly Anchors
- Very Strong Hold in Hollow Walls
- Reliable for Medium to Heavy Loads
- Simple, Effective Mechanism
- Works with Drywall, Plaster, and Hollow-Core Doors
Specific Weight Capacities
| Anchor Size | Typical Load Capacity |
|---|---|
| Small Toggle (1/8″ diameter) | 30–50 lbs (14–23 kg) |
| Medium Toggle (3/16″ diameter) | 50–70 lbs (23–32 kg) |
| Large Toggle (1/4″ diameter or bigger) | 80–100+ lbs (36–45+ kg) |
Always check the box. Some toggle bolts can hold over 100 lbs, but wall quality matters too!
How Does a Butterfly Anchor Work?
- The wings are folded flat to pass through a pre-drilled hole.
- Once inside the hollow space, the wings spring open.
- Tightening the screw pulls the wings tightly against the backside of the wall, anchoring the fastener securely.
Steps to Install a Butterfly Anchor
You’ll Need:
- Butterfly anchor (toggle bolt)
- Drill
- Drill bit (slightly bigger than folded wings)
- Screwdriver
- Stud finder
- Safety glasses
Step 1: Find a hollow spot
Use a stud finder to make sure you’re not over a stud. Toggle bolts need space behind the wall to work.
Step 2: Drill a hole
Pick a drill bit just large enough for the folded wings.
Step 3: Insert the anchor
Fold the wings and push the anchor through the hole.
Step 4: Attach the object
Place your item (shelf bracket, mirror hook, etc.) onto the screw and tighten gently. Stop when it feels snug.
Where Butterfly Anchors Work Best
- Hanging heavy mirrors
- Mounting shelves
- Curtain rods
- Flat-screen TVs (if rated properly)
- Wall-mounted coat racks
Good surfaces: drywall, plaster, hollow-core doors.
Types of Butterfly Anchors
| Material | Best For |
|---|---|
| Plastic toggles | Light-duty (up to ~20 lbs) |
| Zinc-plated steel toggles | Most common, good corrosion resistance |
| Stainless steel toggles | Heavy-duty or humid areas (bathrooms, outdoors) |
When NOT to Use Butterfly Anchors
❌ Solid walls (like brick, concrete, or studs) — use masonry anchors or screws.
❌ Super heavy items (over 150 lbs) — use stronger specialty anchors.
❌ Very thin walls — there’s no space for the wings to open.
Common Mistakes to Avoid
⚠️ Drilling the hole too large — the anchor won’t hold.
⚠️ Choosing a weak anchor for a heavy object.
⚠️ Over-tightening — can break the wall.
⚠️ Not checking for hidden wires or pipes — dangerous!
Quick Installation Tips
- Match the drill bit to the folded wings — not too big!
- Tighten the screw slowly to help the wings seat properly.
- Wear safety glasses when drilling.
- Watch a video tutorial if it’s your first time.
Troubleshooting Installation Problems
Problem: Anchor keeps spinning
Solution: The hole might be too big. Fill it with patch compound and try again.
Problem: Wings won’t expand
Solution: Check that you inserted the anchor far enough to clear insulation or obstacles inside the wall.
Problem: Screw won’t tighten properly
Solution: The wings might not have opened fully. Remove and retry.
How to Remove a Butterfly Anchor
- Unscrew the bolt fully.
- Push the toggle wings into the wall cavity.
(The wings are lost inside the wall — this is normal.)
Important:
If it’s a molly bolt (not a toggle bolt), removal is different:
- Remove the screw.
- Pry out the sleeve gently with a flathead screwdriver or hammer the sleeve slightly inward and patch the hole.
Comparison with Other Wall Anchors
| Anchor Type | Best Use | Pros | Cons |
|---|---|---|---|
| Plastic Wall Plug | Light-duty hanging | Very easy, cheap | Weak in hollow walls |
| Molly Bolt | Medium-duty in drywall | Expands and stays flush | Harder removal |
| Butterfly Anchor | Medium to heavy-duty in hollow walls | Very strong | Requires large hole |
Summary: Butterfly anchors are ideal when you need serious strength in hollow walls.
Cost Information
| Type | Typical Price Range |
|---|---|
| Plastic toggle (pack of 10) | $3–$7 |
| Zinc-plated toggle (pack of 10) | $6–$15 |
| Heavy-duty stainless toggle (individual) | $2–$5 each |
Tip: Buying kits often saves money if you have multiple installations.
Safety Precautions
- Always use a stud finder to check for hidden wiring or plumbing.
- Always wear safety glasses while drilling.
- Never exceed the manufacturer’s specified weight rating.
- If mounting extremely heavy loads, consult a professional.
Quick Visual: How It Looks
Before inserting: Wings folded against the screw.
Inside the wall: Wings pop open.
After tightening: Wings clamp tight behind the wall.
Think about a butterfly squeezing through a hole, then spreading its wings — that’s exactly what happens
Conclusion
Butterfly anchors are your go-to solution for hanging heavy items securely on hollow walls.
By understanding their proper usage, weight capacities, and installation techniques, you can make your DIY projects safer and more professional-looking.
Follow the right steps, avoid common mistakes, and choose the correct size — and your walls will thank you!