How to install concrete wedge anchors?

Correct installation is the key to a successful application once an anchor has been selected. A properly drilled hole is essential for ease of installation and optimal anchor performance.


Using the correct diameter drill bit (bit diameter is the same as anchor diameter), drill a hole into the base material to a depth of at least 1/2" or one anchor diameter deeper than the embedment required. Most concrete wedge anchors are designed to be installed in holes drilled with carbide-tipped bits meeting the requirements ANSI Standard B212.15. The following table lists the nominal drill bit diameter and the tolerance range established by ANSI for carbide tip drill bits.

Nominal Drill ANSI Standard Nominal Drill ANSI Standard
1/8" 0.134 - 0.140" 11/16" 0.713-0.723"
5/32" 0.165-0.171" 3/4" 0.775 - 0.7B7"
11/64" 0.181 - 0.187" 27/32" 0.869 0.881"
3/16" C. 196 -0.206" 7/8" 0.905 - 0.917"
7/32" 0.229 - 0.237" 15/16" 0.968 - 0.980"
1/4" 0.260 - 0.268" 1" 1.030-1.042"
9/32” 0.296 - 0.304' 1-1/8" 1.160 1.175"
5/16" 0.327 - 0.335" 1-1/4" 1.285-1.300"
3/8" 0.390 - 0.398" 1-3/8" 1.410-1.425"
7/16" 0.458 - 0.468" 1-1/2" 1.535-1.550"
1/2" 0.520 - 0.530" 1-5/8" 1.655-1.675"
9/16" 0.582 - 0.592" 1 -3/4" 1.772-1.792"
5/8" 0.650 - 0.660" 2" 2.008 - 2.028"

Anchor holes should be thoroughly cleaned before the installation of the anchor. Remove the dust and debris from the hole during drilling (e.g., dust extractor, hollow bit) or following drilling (suction, forced air) to extract loose particles. This procedure is achieved using compressed air, a pump, or a vacuum with an extension. Dust and other debris must be removed from the hole to allow the concrete wedge anchor to be installed to the required embedment and to ensure that the expansion and engagement can be properly attained.


Position the washer on the anchor and thread on the nut. When installing through a fixture, drive the wedge expansion anchors through the fixture into the hole. Be certain the anchor is driven to the minimum required embedment depth.


Tighten the anchor with a torque wrench by applying the required installation torque. The threaded stud will draw up during the tightening of the nut; the expansion wedge clip remains in its original position.

Concrete Wedge Anchor


do- anchor diameter

dh- minimum diameter of hole clearance in the fixture

dbit- nominal drill bit diameter

hnom- minimum nominal embedment depth

ho- minimum hole depth

length identification mark indicates the overall length of the anchor

Click for technical data on concrete wedge anchors.


What is a concrete wedge anchor used for?

A wedge expansion anchor is a mechanical device used for fastening structural steel like beam and column anchorage, facades, electrical and mechanical equipment, cable trays and strut, pipe supports, fire sprinkler, handrails, and racks into concrete materials.

Are concrete wedge anchors removable?

Wedge expansion anchors are not designed to be removed from the base material.


Which is better: concrete wedge anchor or sleeve anchor?

It depends on the application. Both can be used in concrete brick and block, but wedge anchors have much higher ultimate and allowable load capacities.


What is a wedge-type anchor?

Anchor types that load transfer mechanisms based on friction are generally “expansion anchors”. These anchor types are designed with expansion elements that compress against the wall of the drilled hole. When the anchor is loaded, the frictional force between expansion elements and concrete allows the anchor to transfer the load to the base material. Torque-controlled expansion anchors are installed by applying a specified torque to the bolt head or nut with a torque wrench. Torque-controlled expansion anchors may be further classified as either sleeve type or bolt type (also commonly named “wedge anchor”)


How deep should the hole be drilled for a wedge anchor?

The minimum hole depth depends on the nominal diameter of the anchor, type of anchor tested and base material. See charts below:

How deep should the hole be drilled for a wedge anchorWedge Anchor Installation Chart


How much weight can a wedge anchor hold?

Using the Allowable Stress Design (ASD) method, allowable load calculations are based on the application of a safety conversion factor to the mean result of laboratory testing for the ultimate load. The safety factor is intended to account for reasonably expected variations in loading.


Converted Allowable Loads for Wedge Anchors

Wedge Anchors Load Capacity in concrete



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