A wedge anchor (Dutch: keilbout) is a heavy fixing (expansion anchor) used to fasten something firmly to concrete, natural stone or solid masonry. The bolt has a cone (wedge) at the end with a metal expansion sleeve around it. As it is tightened, the cone is drawn into the sleeve, which is forced open and grips the wall of the drilled hole.
How it works
The wedge anchor works by clamping (expansion force), not by adhesive:
- Drill — a hole of the correct diameter and depth in the solid material.
- Place — push the wedge anchor with its sleeve into the hole.
- Tighten — the cone draws into the sleeve, which clamps against the hole; the harder you tighten, the firmer the grip.
This lets a wedge anchor take high tensile and shear loads.
Application
- Heavy structures — steel sections, brackets, machines and railings on concrete.
- Facades and canopies — fixing load-bearing components.
- Construction and industry — wherever a high, reliable load is needed.
Points to watch
- Only suitable for solid, load-bearing bases; in hollow block or aerated concrete an expansion anchor does not hold reliably — use a chemical anchor or hollow-wall fixing there instead.
- Keep to the specified drill diameter, drill depth and edge distance; too close to an edge the material can break out.
- For damp or outdoor situations choose a galvanised or stainless steel version.
Related terms
- Chemical anchor
- Hollow-wall plug
- Anchor
- Reinforcement
- Steel
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