Wedge anchors, or concrete wedge anchors, are an essential tool used to anchor objects in a wide array of industries. There are various different types used for the same purpose but under different conditions. Below, we'll take a close look at what concrete wedge anchors are, how they work, and the different types you're likely to encounter.
What Are Wedge Anchors?
Concrete wedge anchors are a type of fastener. Their main use is for securing heavy objects to cement, concrete, and other types of masonry.
They consist of three main parts, namely:
- a threaded rod
- a metal clip
- a tapered expansion wedge
How Do Wedge Anchors Work?
Drilling a hole into the masonry or concrete surface, inserting the wedge anchor, and then tightening the nut on the threaded rod constitute the installation procedure. The clip expands and firmly grips the sidewalls of the hole as the nut is tightened because the wedge is being forced up inside it.
Where Are Concrete Wedge Anchor Fasteners Used Regularly?
Some of the industries where you'll commonly encounter wedge anchors include the following:
- Construction: Mainly used to secure structural elements to concrete or masonry.
- Infrastructure: Typically used to fasten guardrails, signposts, and other items to roadways, railway tracks, and other structures.
- Manufacturing: Manufacturing companies often use a type of concrete wedge anchor to attach heavy machinery and other items to the floor for safe operation.
- Marine and Offshore: Many different Marine and offshore industries use wedge anchors to attach equipment and structures to docks, oil rigs, and other concrete structures.
- Commercial and Residential: In the home or commercial buildings, wedge anchors may be used to attach everything from handrails to curtain rods. Anywhere that requires a solid fastener to attach something to a masonry surface.
- Utilities: Wedge anchors are often used by utility companies to install street lamps and other structures to concrete bases.
- Retail and Warehousing: Retail stores and warehouses may use wedge anchors to install and secure anything from heavy shelving units to racks and other forms of storage.
- Transportation: In the transportation industry, wedge anchors are used to fasten bike racks, bollards, transit shelters, and other items or structures to concrete or masonry platforms.
- HVAC and Plumbing: Wedge anchors are useful in the air conditioning and heating industries as they provide an ideal way to safely attach HVAC units, ductwork supports, and even plumbing fixtures to concrete or masonry walls and floors.
- Entertainment and Events: The events industry often employs temporary structures. These may include stages, signage, and other types of platforms. Solid concrete wedge anchors offer the ideal solution for fastening these tightly without fear of collapse.
Types of Wedge Anchors
There are many different types of wedge anchors that find uses in different applications. Different materials are suitable for different levels of exposure to the elements and may have different strength thresholds. Let's take a closer look at the different types and their best uses.
Standard Wedge Anchor
The standard wedge anchors consist of normal steel. They're not plated with anything, so they're better for interior use than use outdoors. However, they'll attach just about anything to solid concrete. These anchors are commonly used indoors for putting up shelves, curtain rails, and even machinery.
Some companies may specify that they sell carbon steel wedge anchors. However, in the case of these fasteners, it won't necessarily make much of a difference.
Stainless Steel Wedge Anchor
Stainless steel is the best option if you require something with a high level of rust resistance. Typically, if you're going to use wedge or expansion anchors outdoors, you'll be using stainless steel.
It's worth noting that there are two different types of stainless steel that you're likely to encounter. Namely, these are 18-8 stainless steel and 316 stainless steel. Both are fantastic and have similar strength and durability. However, 316 has a much higher level of corrosion resistance.
Zinc-Plated Wedge Anchor
Zinc-plated expansion anchors are used in interior applications where rust and corrosion are not a concern. They have lower rust resistance, so they aren't suitable for exposure to the elements. However, if you have to choose between zinc-plated steel and normal steel, zinc-plated steel will be better able to handle moisture.
How to Install Concrete Wedge Anchors
Installing a concrete wedge anchor is fairly simple as long as you know what you're doing. Here's a step-by-step guide:
- Drilling the Hole:
- Wear appropriate safety gear.
- Mark your intended installation point for the anchor.
- Using a hammer drill and the appropriate masonry bit size, drill the hole to the intended depth.
- Clearing the Hole:
- Use a brush or vacuum to remove dust from your pre-drilled hole.
- Ensure that the hole is deep enough to accommodate the anchor body.
- Inserting the Wedge Anchor:
- Insert the anchor through the fixture (the item you're securing) and into the hole.
- Ensure that the anchor fits fully into the hole and rests flush against the fixture's surface.
- Tightening the Nut:
- To tighten the nut on the anchor's threaded end, use a wrench or socket set.
- The wedge inside the anchor will expand and push up against the sides of the hole as you tighten the nut, providing a firm grip.
- Setting the Anchor:
- As you crank the nut, apply consistent pressure until it is torqued to the manufacturer's suggested amount.
- Do not overtighten, as this could cause harm to the base material or anchor.
- Final Check:
- Before the adhesive or mortar (if you're using it) sets, make sure the fixture is properly positioned and aligned.
- Before putting any strain or stress on the anchor, give it enough time to cure.
And there you have it, you've successfully installed a fastening wedge anchor for your next project.
Choosing Wedge Anchors for Your Project
Before taking on your next project, you should be able to find out exactly which kind of wedge anchors you need. When you're looking at the search results, and don't yet have filters applied, here's what you need to ask:
Which Length Should the Anchor Be?
When calculating this, you need to determine the following:
- How thick the concrete or masonry is that you'll be attaching to?
- The thickness of the item you'll be attaching (fixture) as well as the thickness of the nut.
- The anchor's minimum embedment depth - each manufacturer specifies how deep a specific type of anchor needs to be in order to bear its full load capacity.
- Additional clearance, if desired
To find the length of the anchor you require for your project, follow this formula:
Total Anchor Length = Minimum Embedment Depth + Fixture Thickness + Nut Thickness + Additional Clearance
Now that you've made your calculations, you can determine which diameters and lengths of the anchor will suit your purpose.
Which Kind Of Material Is Best For Your Purpose?
Different materials are suitable for different purposes. In the case of anchor wedges, the materials can be summarized as follows:
- Steel anchors have a low risk of corrosion and are suited for dry indoor conditions.
- For outdoor and harsh situations, stainless steel anchors offer high corrosion resistance.
- Galvanized anchors are frequently used in outdoor applications and give a modest level of corrosion resistance.
- For light-duty indoor use, zinc-plated anchors are suitable because they offer a basic level of corrosion protection.
Troubleshooting and Common Issues
Wedge anchors are generally fairly easy to use. However, there are a few things that can go wrong if you don't use them correctly. Some of the most common problems you may encounter include the following:
- Insufficient Embedment Depth - If wedge anchors aren't anchored deep enough, they won't have their full strength or load-bearing capacity.
- Over-Tightening - Overtightening can damage the concrete or masonry, creating unstable anchoring.
- Under-Tightening - Under-tightening leads to deterioration. Because the anchor isn't fully fixed in the hole, it may pull out of the base.
- Improper Hole Diameters - Improper hole diameters may lead to anchors pulling out of the wall or not fitting in the hole.
- Surface Cracking - Installing a wedge anchor may cause superficial cracking in old or brittle masonry.
- Incorrect Material Selection - Choosing the wrong material may lead to insufficient strength or excessive corrosion.
- Corrosion - Rust may be a problem if you choose the wrong material for exposure to the elements.
- Vibration and Movement - Over time, wedge anchors may become loosened as a result of movement, vibration, or dynamic loads.
- Installation Errors - Reduced anchor performance may be the result of inaccurate drilling, poor hole cleaning, or failure to install an anchor in accordance with manufacturer recommendations.
- Inadequate Load Capacity - Safety concerns and weakened structural integrity may result if the size and kind of anchor utilized do not match the required load requirements.
- Aging and Deterioration - Even wedge anchors that have been properly installed may develop wear, corrosion, and degradation over time, potentially lowering their capacity to support loads.
Sleeve Anchor Vs. Wedge Anchor
Sleeve anchors are similar to wedge anchors, but there are a few differences between them. When comparing sleeve anchor vs. wedge anchor, some of the main differences include:
- Sleeve anchors can be used on more different substrates than wedge anchors.
- Wedge anchors have higher sheer resistance and greater strength than sleeve anchors.
- Sleeve anchors are sometimes considered more versatile than their wedged counterparts.