Mechanical Anchoring Solutions
Post-installed mechanical anchors come in many shapes and sizes with equally different fastening mechanisms offering low to high holding capacities. Hilti’s mechanical anchor portfolio offers something for every designer from low capacity removable screw and sleeve anchors to medium-duty wedge anchors to high capacity expansion and undercut anchors.
Commonly known as concrete anchors, though many are also suited for installation in masonry, mechanical anchors do not have the installation and in-use temperature restrictions of their adhesive anchor counterparts. Additionally, mechanical anchors can be loaded immediately after installation whereas an adhesive anchor must be fully cured before loading. This flexibility offers design freedom to the specifier and added productivity to the contractor.
Why choose mechanical anchors on your project?
You may be asking yourself, “What differentiates an expansion anchor from an undercut anchor from a screw anchor and why should I choose one over the other for my project?” That’s an excellent question and the answer lies in the way the load is transferred from the anchor to the base material. While adhesive anchors transfer loads to the base material via the bond of the adhesive element, post-installed mechanical anchors transfer the load to the base material through bearing, friction or keying.
Wedge anchors transfer loads by friction, and to some extent bearing / keying. Examples of these anchors are the Kwik Bolt TZ, Kwik Bolt 3 and the HSL-3. Screw anchors are inserted into a drilled hole that is typically smaller in diameter than the actual anchor. The loads are then transferred to the base material by keying. An example of a screw anchor is the Kwik HUS-EZ. Undercut anchors derive their holding strength from the mechanical bearing interlock provided from the undercutting of the concrete at or near the bottom of the hole achieved either by a special tool or by the anchor itself during installation. An example of an undercut anchor is the HDA.
Understanding how different mechanical anchors transfer loads to which base materials is key to understanding which anchors provide the appropriate holding values for your loading situation and knowing which one to select for your next project design.