Wedge Anchor Concrete

Wedge Purchase Wedge Anchors

A wedge anchor for concrete is a special type of concrete fastener designed for use in concrete.  Concrete wedge anchors cannot be used in brick, block or other masonry base materials that are not made from solid concrete.  The concrete wedge anchor is made from carbon steel that is either zinc plated, hot-dipped galvanized or stainless steel.  Each concrete wedge anchor comes packaged with the correct size and number of nuts and washers.

Types of Concrete Wedge Anchors
Different types of concrete wedge anchors are manufactured for use in different applications.  The only differences between the different types of concrete wedge anchors is the material that they are made from and the plating or coating that is used for improving the corrosive resistance of the steel.  

Carbon Steel – the carbon steel concrete wedge anchor comes with either zinc plating for indoor applications where moisture is not present or hot-dipped galvanized coating for outdoor applications where moisture may be present.  Stainless Steel 303/304 – different manufacturers use either the 303 or 304 stainless steel for their concrete wedge anchors. They are used in applications where moisture is present or where the application is submerged in water.
Stainless Steel 316 – the highest grade of stainless steel that concrete wedge anchors are made from, and are for use in submerged applications and where some chemicals are present, such as chlorine in and around a swimming pool.

Description
Concrete wedge anchors are made from a single bar of steel that is threaded on one end, and the other end is necked down with a permanently attached clip. They are packaged with the correct nut and washer.

Available Diameters
Concrete wedge anchors come in nine different diameters ranging from 1/4” to 1-1/4”.

Available Lengths
Each diameter of concrete wedge anchor is available in different lengths from 1-3/4” in the 1/4” diameter to 12” long in all diameters larger than 1/2”.

Determining Diameter
The diameter of concrete wedge anchor to use for any particular application depends on the weight of the object being fastened, on the diameter of the hole size in the object being fastened and on any specifications of diameter recommended by an engineer. The rule of thumb is that the larger the diameter then the better the holding values.  
Holding values for Concrete Fastening Systems, Inc. wedge anchor can be found at http://www.confast.com/products/technical-info/thunderstud-anchor.aspx

Length to Use
The length of concrete wedge anchor to use is based on the thickness of the material being fastened plus the embedment depth of the concrete wedge anchor into the concrete.  Each diameter of concrete wedge anchor has a minimum embedment depth that the anchor must be inserted into the concrete for it to obtain minimum holding values.  Adding the minimum embedment of the diameter of concrete wedge anchor being used to the thickness of the material being fastened plus the thickness of the nut and washer will give the minimum length of concrete wedge anchor that should be used.  Minimum embedment depths for each diameter of concrete wedge anchor are listed below:

Wedge Anchor Diameter

Minimum Embedment

3/8”

1-1/2”

1/2”

2-1/4”

5/8”

2-3/4”

3/4”

3-1/4”

7/8”

3-7/8”

1”

4-1/2”

1-1/4”

5-1/2”


Hole Diameter
The diameter of hole to drill for a concrete wedge anchor is equal to the diameter of the concrete wedge anchor being installed.  A 5/8” concrete wedge anchor requires a 5/8” hole to be drilled into the concrete.

Hole Depth
The hole in the concrete needs to be drilled a minimum of 1/2” deeper than the concrete wedge anchor will penetrate into the concrete.  This extra space is required to make sure that the concrete wedge anchor does not bottom out in the hole before reaching the intended embedment depth, and also allows for any dust that may be created during the installation to fall out of way.

Concrete Wedge Anchor Installation:
  1. With a hammer drill in the hammer mode and a carbide tipped drill bit that meets ANSI standard B212.15 and is also the same diameter as the diameter of the concrete wedge anchor being installed, drill a hole in the concrete.
  2. Drill the depth of the hole a minimum of 1/2” deeper than concrete wedge anchor will penetrate, or 1/2” deeper than the minimum depth of embedment.
  3. Using a wire brush, compressed air or vacuum, clean the hole of all debris and dust.
  4. Thread nut onto threaded end of concrete wedge anchor so that the top of the nut is flush with the top of the concrete wedge anchor. This will protect the threads from damage during installation.
  5. Insert concrete wedge anchor, clipped end first, into the predrilled hole in the concrete.  If the concrete wedge anchor is being installed through a hole in a fixture, make sure that the hole diameter is larger than the diameter of the concrete wedge anchor being used.
  6. With a hammer, strike the nutted end of the concrete wedge anchor until a minimum of 6 threads are below the surface of the concrete or below the surface of the item being attached.
  7. Using your fingers, tighten the nut.
  8. Take a wrench and turn the nut clockwise 2 to 3 turns or until the proper torque values for the diameter of wedge anchor being used are obtained.


 

Please remember with all fastening jobs to keep safety in mind. Always follow safety instructions on all tools, and refer to manufacturer's installation instructions when available and always remember to wear safety goggles!

Article written by: Michael Pistorino, Concrete Fastener Specialist