Abstract: An assembly for inserting an attachment coil in concrete with a screw having a releasable spacer and an expandable coil mounted thereon. The spacer initially positions the screw in a hole for location of the coil and has a slot to permit the spacer to pop off the screw as the screw is screwed into the coil in the hole. The spacer may have longitudinal ribs to bridge any lateral space between the screw and the hole. The coil has an exterior diameter less than the interior diameter of the hole for free movement of unexpanded loops without creating cross threading during insertion. A second coil can be inserted closer to the surface by assembling two spacers on a screw for location of the second coil, with both spacers popping off the screw as the screw advances into both coils. The use of two coils in a hole allows positioning of coils in both compression and tension zones on opposite sides of a neutral axis of the structure.