Hilti Wedge Anchors

     The Hilti wedge anchor, called the Kwik-Bolt, also has a number of other related products called the Kwik-Bolt 3 as well as the Kwik-Bolt –TZ, which has been tested for fastening where the concrete is cracked or may become cracked. The Kwik-Bolt 3 is the standard type of wedge anchor and is the topic of the following article.
     The Kwik- Bolt 3 has a number of features and benefits. One convenient feature is the end of the Kwik-Bolt 3, which can be inserted into the hole first because it is rounded to allow for easy installation.  The threaded end is dog pointed to help prevent thread damage during installation.  The Kwik-Bolt 3 comes with standard threads for applications where higher shear value is required and longer threads where installation flexibility is required.   The Kwik-Bolt 3 is available in zinc plated carbon steel, hot-dipped galvanized, 304 stainless steel and 316 stainless steel for applications in different environments.
     Both the Kwik-Bolt 3 and the Kwik-Bolt TZ are designed for use in solid concrete and give consistent performance for a wide range of mechanical anchor applications such as handrails, storage racks, pipe supports and guardrails.  The zinc plated carbon steel Kwik-Bolt is used in dry indoor applications whereas the hot-dipped galvanized is used in outdoor application where moisture may be present.  The 304 is used for wet enjoinments and the 316 is used for submerged enjoinments where some chemicals may be present.
     The zinc plated carbon steel Kwik-Bolts in both the standard threaded and the long threads come in six different diameters: 1/4”, 3/8”, 1/2”, 5/8”, 3/4” and 1”.  The hot-dipped galvanized Kwik-Bolt 3 comes in only three diameters of 1/2”, 5/8” and 3/4”.
Both the standard thread and long threaded 304 stainless steel Kwik-Bolts come in six diameters of 1/4”, 3/8”, 1/2”, 5/8”, 3/4” and 1”.  The 316 stainless steel Kwik-Bolt comes in standard threads in diameters of 1/4”, 3/8”, 1/2”, 5/8”, 3/4” and 1”. 
     There are two other special Kwik-Bolt 3 types that are designed for special applications and do not come with a nut and washer.  The rod hanger Kwik-Bolt 3 is 3/8” x 2-1/4” with a 3/8” rod coupler for hanging threaded rod from ceiling applications and is zinc plated carbon steel.  A flat head counter sunk post headed Kwik-Bolt 3 is available in two diameters of 1/4” and 3/8” and comes in the zinc plated carbon steel or stainless steel.
     Each diameter of Hilti Kwik-Bolt comes in different lengths, and the lengths are different for each diameter.  The minimum length of Kwik-Bolt 3 to use for any particular is determined by adding the thickness of the material to be fastened to the minimum embedment for the diameter of anchor being used, plus space for the nut and washer.  The diameter to use for any particular application is determined by a number of different factors.  First, the weight of the object being fastened is the first consideration. The heavier the object being fastened then the larger the diameter of wedge anchor that should be used.  Secondly, the hole in the object that is being fastened must be considered since the Kwik-Bolt must be small enough to fit through the hole. Finally, depending on the application and engineer, there may be a specified diameter and length of Kwik-Bolt to be used in specific applications. If this is the case, then what the engineer has specified should be used.
     When installing the Kwik-Bolt 3, a hole must be drilled into the concrete. The diameter of the hole is equal to the diameter of the anchor.  The hole must be drilled using a hammer drill that is set in the hammer and rotation mode, and using a carbide tipped bit that meets ANSI standards.  The tolerance between the hole diameter and anchor diameter is critical; using an ANSI standard bit insures the hole size. After the hole is drilled, it is important that the hole is cleaned out using a wire brush, vacuum or compressed air. The depth of the hole should be a minimum of 1/2” deeper than the Kwik-Bolt 3 would penetrate the concrete.  This extra space at the bottom of the hole allows room for any dust and debris to fall into during the installation process.   The Kwik-Bolt 3 does not use the bottom of the hole to be set, so the hole can be any depth as long as it is deep enough to insure that the anchor is embedded after expansion to minimum embedment depth for the diameter being installed.
     All wedge anchors work on the same principles and are made from essentially the same material; the biggest difference is the style of the expansion clip.  The Hilti Kwik-Bolt is manufactured by Hilti .  Concrete Fastening Systems, Inc stocks a complete line of American made wedge anchors that include the zinc plated carbon steel, hot-dipped galvanized and stainless steel.




 

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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