Anchor Selection Guide
This anchor selection guide was developed for FEMA and is available in their manuals FEMA-412, FEMA-413, and FEMA-415. *** Subscribe Today ***
Adhesive Anchors: Adhesive anchors come in many shapes and sizes with different types of adhesives. Epoxy type is used by mixing two or more components usually with a mixing nozzle. Acrylic adhesive dispenses and cures quickly.
Heavy Duty Undercut Anchors
Heavy Duty Undercut Anchors: Used in heavy-duty applications. Typically two types: self-undercutting and adhesive. Self-undercutting use a special undercutting drill bit. Some undercutting anchors use carbid tipped anchors that cut into the concrete without a special drill.
Wedge Anchors: The most common concrete anchor for heavy to light applications. Many configurations are available for most applications.
Sleeve Anchors: Universal anchor for light to medium duty applications. Multiple head designs fit many applications and is especally useful in masonry (Bed Joint).
Shell Anchors: Flush mount to sub-surface internally threaded anchor for light to medium duty applications. A special setting tool is required to properly install and must be supplied by the manufacture for each specific anchor. Causes high stress in the concrete, and there is a lot of concern in the use of these anchors by some engineers.
Headed Studs: These are not a post installed anchor. They are installed when the concrete is poured into place. They are especally good for heavy loads.
Lag Bolts: Lag bolts are not a concrete anchor. They are only used for connecting equipment to a wood structure. Torque of lag bolts is not recommended. Tighten until snug to prevent overtightening and failure of the bolt.
Self Tapping Screws
Self Tapping Screws: Self-tapping screws are used only for light weight metal shapes as in studs used for drywall construction. When attaching to drywall, span three studs with brackets.
Keyed Adhesive Anchors
Keyed Adhesive Anchors: This is just another type of adhesive anchor. This particular design is for masonry where a screen is inserted into a drilled hole with the epoxy or acrylic adhesive before inserting the anchor.
Concrete Screw: Good for light to medium duty applications and available in many diameters and lengths.
Umbrella: Umbrella is another type of adhesive anchor. Used in masonry positioned in the middle of the open cell.
Toggle Bolt: Toggle or "Molly" anchor is used for light to medium duty. Some anchors are supplied with bolts or screws. One piece and two piece designs are available.
Steel Bolting: Typical connection in the construction industry for assemly for steel shapes. Should always use a washer.
Embedded Plates: Embedded steel plates are flexible. Attachment is typically welding the structural steel shape to the plate.
Large Concrete Screw
Large Concrete Screw: This is a newly designed anchor. Available for heavy duty applications. Is considered an undercut anchor. Installation is simpler than most anchors combined with its allowable loads makes this anchor very popular.
J-bolts: J-bolts are similar to headed studs in that they are not a post installed anchor. They are installed when the concrete is poured. Except that installation problems where testing has shown them to fail and pull out during the test.