Hot Dipped Galvanized Anchor Bolts

Hot-dipped galvanized anchor bolts are designed for use in moist outdoor environments.  The anchor bolt is dipped into the galvanized material to coat the steel with a thick material that helps prevent rust.  Hot-dipped galvanized anchor bolts have more rust resistance than the standard zinc plated and the mechanically galvanized anchor bolts.  The term anchor bolt is another name for a wedge anchor. The wedge anchor is a post -installed type of concrete anchor, which means that the wedge bolt is installed after the concrete is hardened.

Applications
Hot-dipped galvanized wedge anchor bolts are designed for use in solid concrete. They should never be installed into soft, hollow base materials.  The hot-dipped galvanized coating is excellent for use in moist atmospheres where more rust resistance is required than the standard zinc plated wedge anchors can provide.  The hot-dipped galvanized wedge anchor bolts have more rust resistance than the mechanically galvanized wedge anchor bolts, but not more than stainless steel.

Available Diameters
The hot-dipped galvanized wedge anchor bolts come in diameters ranging from 3/8" to 1-1/4".  Each diameter of hot-dipped galvanized wedge anchors bolts come packaged with the correct size and number of nuts and washers that are hot-dipped galvanized and will match-up with the threads on the anchor.  Standard nuts and washer will not work with a hot-dipped galvanized wedge anchor bolt, because the threads are manufactured differently to allow for the thick galvanized material.

Available Lengths
Each diameter of hot-dipped galvanized wedge anchor bolt comes in a number of different lengths to allow for a wide range of material thickness that might need to be fastened.  The 3/8" diameter comes in a shorter length of 2-1/4" while the longest length of 12" is available in diameters of 1/2", 5/8", 3/4", 7/8", 1" and 1-1/4".

Holding Values
The holding values of a hot-dipped galvanized wedge anchor bolts depends on the diameter of wedge anchor bolt being installed, the depth of embedment and the hardness of the concrete base material.

  • The larger the diameter of hot-dipped galvanized wedge anchor bolt that is installed then the better the holding values will be.  A 1/2" diameter hot-dipped galvanized wedge anchor bolt has more holding strength than a 3/8" hot-dipped galvanized wedge anchor bolt.
  • Each diameter of hot-dipped galvanized wedge anchor bolt must be installed to a minimum depth to insure minimum holding values in the concrete.  The deeper a hot-dipped galvanized wedge anchor bolt is embedded into the concrete then the better the holding values.
  • The harder the concrete is that the hot-dipped galvanized wedge anchor bolt is installed, then the better the holding values will be.  Concrete hardness is measured in psi (pounds per square inch). For comparison purposes, it shows up in charts as 2000 psi, 3000 psi or 4000psi.

 

Hole Diameter
A hole must be drilled into the concrete for the hot-dipped galvanized wedge anchor bolt to be installed.  The diameter of the hole is equal to the diameter of the hot-dipped galvanized wedge anchor bolt being installed.  A 5/8" hot-dipped galvanized wedge anchor bolt requires a 5/8" drilled hole.

Depth of Hole
The hole should be drilled deeper into the concrete than the embedment depth of the hot-dipped galvanized wedge anchor bolt.  A minimum of 1/2" deeper is required to insure that the wedge anchor bolt will not bottom out in the hole and to allow space for any debris to fall that is created during the installation process.

Drilling Hole
The hole that is drilled into the concrete for the hot-dipped galvanized wedge anchor bolt must be drilled using a hammer drill in the hammer mode and using a carbide tipped bit that meets ANSI standards.  It is critically important that the drill bit meet ANSI standards because this will insure proper tolerance between anchor diameter and hole diameter.

Installation
Using a hammer drill in the hammer mode, drill a hole in the concrete using a drill bit that has a carbide tip, meets ANSI standards and is equal in diameter to the diameter of the hot-dipped galvanized wedge anchor bolt being installed.

  • Make sure that the hole is drilled a minimum of 1/2" deeper than the hot-dipped galvanized wedge anchor bolt will penetrate the concrete.
  • With a wire brush, vacuum and compressed air, clean the hole of all debris and dust.
  • Install the nut onto the threaded end of the hot-dipped galvanized wedge anchor bolt by threading it on until the top of the nut is flush with the top of the wedge anchor bolt.
  • Insert the wedge anchor bolt into the concrete, clip end first.
  • Using a hammer, strike the nutted end of the wedge anchor bolt until a minimum of 6 threads are below the surface of the concrete in order to meet minimum embedment requirements.
  • Finger tighten the nut.
  • With a wrench, turn the nut clockwise 2 to 3 turns or until the proper torque values 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: Bob Carlisle, President Concrete Fastening Systems, Inc

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