The DUC Undercut Anchor consists of a ASTM A36 or A193 Grade B7 threaded stud, a thick walled expansion sleeve, an expander coupling and a nut and washer.
The DUC Undercut Anchor is installed into a pre-drilled hole which has been enlarged at the bottom in the shape of a reversed cone. The reverse cone is created using the Covert Operations DUC Undercutting Bit which fits into SDS or SDS-Max rotary hammer drills and guarantees the correct angle of the reverse cone. The anchor is expanded into the reverse cone when the nut is turned and the expander coupling is pulled up into the expansion sleeve.
The result is an anchor which transfers load mainly through bearing, and unlike a typical expansion anchor (sleeve, heavy duty sleeve, wedge and drop-ins), is not dependent upon friction between the expansion sleeve and the concrete. Due to the use of a thick walled expansion sleeve, the load is distributed to a large area which virtually insures ductile behavior of the anchor even at relatively shallow embedments.
The DUC Undercut Anchor has been tested to the requirements of ACI 355.2 for use in seismic and cracked concrete applications, and meets the 2003 IBC and ACI 318-02 Appendix D.
DUC Undercut Anchor Advantages vs. Heavy Duty Sleeve and Expansion Anchors and other undercut systems