Lag Shield
Anchors · lag shield anchor · lead shield · expansion shield
Definition: A lag shield is an expandable sleeve inserted into a drilled hole that grips concrete, brick, or block as a lag screw is driven into it.
Anatomy
■ Body■ Internal thread
Governing standards: Manufacturer specified (no universal standard)
Common Sizes
| Inch | Metric | Head width | Head height |
|---|---|---|---|
| for 1/4 lag | M6 | 1/2 drill | 1-1/4 long |
| for 3/8 lag | M10 | 5/8 drill | 1-1/2 long |
| for 1/2 lag | M12 | 3/4 drill | 2 long |
Representative sizes. Full dimensional data lives in the standards listed below.
Grades & Strength
| Grade | Material | Tensile (psi) | Marking |
|---|---|---|---|
| Zinc | zinc alloy / steel | — | None |
| Lead | lead alloy | — | Older, softer |
Materials
- Zinc alloy
- Steel
- Lead alloy
Pros & Cons
Pros
- Works in brick, block, and concrete
- Uses a common lag screw
- Forgiving of hole size
Cons
- Lower capacity than wedge anchors
- Shield must match the hole depth
- Not removable
Typical Uses
- Brick and block fastening
- Concrete medium-duty
- Ledgers and brackets
- Fencing hardware
Alternatives & Related
- Sleeve Anchor — One-piece anchor with a stud instead
- Concrete Screw — Direct screw-in fastening
Where to Buy
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FAQ
What drill size for a lag shield?
Match the drill to the shield outside diameter — e.g. a 1/2 in drill for a 1/4 in lag shield. The shield should be a snug tap-in fit.
Lead vs zinc lag shield?
Zinc shields are stronger and corrosion-resistant; lead shields are soft and mostly legacy. Use zinc for new work.