Plastic expansion anchors
Plastic expansion anchors are sleeve-style anchors that are pressed into a pre-drilled hole. As a screw is driven in, the sleeve expands and grips the surrounding material. Best suited for masonry, concrete, brick, and tile — not for unsupported drywall.
How they work
The hollow plastic sleeve is inserted into a hole slightly smaller than the anchor's outer diameter. Driving the matched screw into the sleeve forces it to expand radially, wedging it tightly against the hole walls. Holding strength comes from friction between the expanded sleeve and the base material.
Pilot hole sizes by anchor size
| Anchor designation | Screw size | Pilot hole (masonry) | Typical load (concrete) |
|---|---|---|---|
| #6 anchor | #6 | 3/16" | ~25 lbs shear |
| #8 anchor | #8 | 1/4" | ~40 lbs shear |
| #10 anchor | #10 | 5/16" | ~55 lbs shear |
| 3/16" anchor | #10–12 | 3/16" | ~60 lbs shear |
Suitable base materials
- Concrete (standard and lightweight)
- Brick and mortar
- Block and CMU
- Ceramic and porcelain tile (over concrete)
- Hard plaster over masonry
Not suitable for
- Unsupported drywall — drywall is too soft; the anchor pulls through under load. Use a toggle bolt or self-drilling drywall anchor instead.
- High-vibration applications — expansion anchors can loosen under repeated vibration. Use a screw anchor or chemical anchor for vibration-sensitive installations.
Buy plastic expansion anchors
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