Screw anchors work by providing a secure point for screws to grip in materials like drywall where screws alone would easily pull out. They achieve this by expanding or gripping the material behind the surface.
Here's a breakdown of how they function:
- Pilot Hole (Usually Required): Most screw anchors need a pilot hole drilled into the drywall first. This helps guide the anchor and ensures a clean insertion.
- Anchor Insertion: The screw anchor is then pushed or screwed into the pilot hole.
- Expansion/Grip: The key mechanism of a screw anchor is how it expands or grips the material. As the screw is tightened into the anchor, the anchor will expand. The back of the anchor essentially flares out or spreads against the back of the drywall, increasing the surface area and preventing it from being pulled through the wall. Some types use threads that bite directly into the drywall.
- Secure Hold: This expansion or gripping action creates a much stronger hold than a screw alone, distributing the force over a larger area of the drywall. This is especially important because drywall itself is relatively weak and prone to crumbling.
In summary: Screw anchors enable screws to be used effectively in drywall by providing a larger, more secure gripping surface behind the drywall panel.
