In concrete construction, attaching something to concrete is usually done with an anchor. With enough foresight, and precise tolerances, we can cast the anchors into the concrete. Often, though, we need to install an anchor into hardened concrete. Such post-installed anchors are proprietary devices that vary in quality and load capacity. The only way to really know the capacity of a specific anchor is to test it. Traditionally, the anchor manufacturers have tested their own anchors and provided the results to designers and contractors.