Surge Building Product's Hammer Drive Anchor are a reliable fastener designed for use in concrete, block, brick, and stone applications. Constructed with a durable Zamac alloy body, it offers excellent corrosion resistance for long-lasting performance. These 1/4" concrete anchors feature a drive nail, available in carbon steel, ensuring secure and tamper-resistant installation. Our hammer drive rivets are available with a mushroom head, this anchor is ideal for light-duty applications where quick and permanent fastening is needed. Minimum Embedment - 3/4" Hole Diameter - 1/4" (Use a hammer drill with a carbide-tipped bit that complies with ANSI standards to drill the hole) Spacing - Anchors must be spaced a minimum of 2-1/2" (measuring from the centers)