What are Wedge Anchors? And other FAQ
When it comes to anchoring into concrete, few fasteners are as dependable as the wedge anchor. Known for their strength and simplicity, wedge anchors are a go-to solution in construction, manufacturing, and heavy-duty installations. Whether you're mounting structural supports, securing racking systems, or hanging machinery, wedge anchors can be the reliable connection between your project and solid concrete.
In this article, we answer the most common questions our customers have about wedge anchors, so you can get your job done faster, safer, and with confidence.
What is a Wedge Anchor?
A wedge anchor is a mechanical expansion anchor used for fastening items to solid concrete. It consists of a threaded stud, an expansion clip, and a nut/washer. When installed, tightening the nut pulls the wedge clip up into the anchor sleeve, expanding it and locking it in place inside the concrete.
There are many types of concrete anchors and wedge anchors are a great choice, but if you want to learn about the other Types of Concrete Anchor Bolts check out our post covering the other types.
Where Can Wedge Anchors Be Used?
Wedge anchors are designed exclusively for solid concrete, not for brick, block, or unreinforced masonry. They're ideal for:
- Structural steel connections
- Machinery and equipment mounting
- Racking, shelving, and safety rails
- Electrical panels and HVAC supports
- Concrete stairs and walkways
What Sizes Do Wedge Anchors Come In?
Common diameters range from 1/4" to 1-1/4", with lengths from 1-3/4" up to 12"+, depending on application. The size you choose depends on:
- The thickness of the fixture
- Required embedment depth
- Load requirements
Pro Tip: The embedment depth must meet or exceed the manufacturer’s minimum for full holding strength. Always check the spec sheet.
How Do I Install a Wedge Anchor?
Installation is straightforward, but precision matters:
- Drill a hole the same diameter as the anchor using a carbide-tipped drill.
- Clean the hole, use compressed air or a brush.
- Insert the anchor through the fixture into the hole.
- Tap lightly with a hammer until the washer is flush.
- Tighten the nut to expand and set the anchor.
Matt B says: “You can hear the anchor slide when it’s not biting, if you know what to listen for, it tells you if the hole’s oversized.”
Also, clean the hole completely: “You get people who think deeper embedment means stronger hold, but if you don’t clean that hole, you’re just burying it in dust.”
How Do I Avoid Installation Mistakes?
Use a torque wrench or a drill with a clutch. Avoid impact drivers that apply excessive force, which can spin the anchor and ruin the hole.
“We’ve seen wedge anchors spin if you’re using an impact driver without a clutch, once that happens, you’re done. That hole’s toast.” - Matt B
Also, torque it down properly: “I’ve pulled wedge anchors out with just two fingers, because the installer rushed it and didn’t torque it down.”
Do I Need a Special Tool?
You’ll need a hammer, a torque wrench (or drill with clutch), and the correct drill bit. For speed and consistency in larger jobs, pros often use rotary hammers with SDS bits. We have a wide range of concrete drill bits here.
Can Wedge Anchors Be Removed?
Technically, yes, but not easily. Once expanded, they’re permanently fixed in the concrete. Removal generally requires cutting or grinding flush with the surface.
What Materials Are Wedge Anchors Made From?
- Zinc-Plated Steel – Best for indoor, dry environments
- Hot-Dip Galvanized – Great for outdoor or damp locations
- 304 or 316 Stainless Steel – Required for corrosive environments, like coastal or chemical exposure
“People want one anchor to do it all, but you’ve got to match the environment, don’t put zinc wedge anchors near salt or chlorinated pools.” - Matt B
What Is Better: Large Diameter Concrete Screws or Wedge Anchors?
It depends on the application, each has strengths.
Wedge Anchors
- Pros: Time-tested, cost-effective, high load capacities. Great for permanent installations in solid, uncracked concrete.
- Cons: Requires precise hole depth and cleaning. Once installed, they’re not removable. Improper torque can lead to cracking or anchor failure.
- Ideal for: Long-term fastening of heavy equipment, structural steel, base plates.
Large Diameter Concrete Screws
- Pros: Easier and faster to install. No need to clean out the hole. Fully removable and reusable in the same hole (if not stripped). Better for jobs requiring flexibility or future reconfiguration.
- Cons: Slightly more expensive per unit. Requires proper driver and torque control.
- Ideal for: Seismic zones, cracked concrete, racking systems, or situations where anchoring may need to change over time.
Matt B’s Real-World Take:
“Concrete screws are easier for installers, less to think about. Wedge anchors are solid, but screw anchors are more forgiving, especially if you're not drilling to perfect depth or need to reposition. Most pros use screws now.”
Bottom Line:
- Use wedge anchors when cost is critical and permanence is preferred.
- Use concrete screws when flexibility, speed, or cracked concrete ratings are more important.
- For more info, check out our detailed blog: Concrete Screws vs. Wedge Anchors
What’s the Difference Between Wedge Anchors and Sleeve Anchors?
Wedge Anchors: Higher load capacity, but only for solid concrete.
Sleeve Anchors: Lower load, but usable in concrete, brick, and block.
If you're working with concrete and need max strength, wedge anchors are your answer.
How Do I Know Which Length to Use?
The general rule: Length = embedment depth + fixture thickness + washer/nut thickness. Many applications call for minimum 1-1/2" embedment, but heavier loads may require more.
Are Wedge Anchors Reusable?
No. Once a wedge anchor is set, it cannot be reused. Always install a new one.
Can I Use Wedge Anchors in Cracked Concrete?
Not all wedge anchors are rated for cracked concrete. If your project requires this, look for ICC-ES approved cracked concrete anchors, usually labeled in the product specs. Many of Simpson's Strong Bolt 2 Wedge Anchors are intended for use in both cracked or uncracked concrete.
