Simpson CSD25312 1/4″ X 3-1/2″ Countersunk Head Split-Drive Anchor – Zinc, Pkg 100

The Split-Drive anchor is a one-piece expansion anchor that can be installed in concrete, grout-filled block and stone. As the anchor is driven in, the split-type expansion mechanism on the working end compresses and exerts force against the walls of the hole. The Countersunk head allows for a smooth surface when attaching wood or light gauge steel to concrete and grout-filled block surfaces.
Installation:

• For Common Rafters:
• Drill a hole in base material using a 1/4″-diameter carbide-tipped drill. Drill hole to specified embedment depth and blow clean using compressed air. (Overhead installation need not be blown clean.) Alternatively, drill hole deep enough to accommodate embedment depth and dust from drilling. Position fixture and insert split-drive anchor through fixture hole.
• For CSD, 3/8″-diameter fixture hole is recommended for hard fixtures such as steel. For DSD, 5/16″-diameter fixture hole is rec