Small diameter Concrete Anchor Screws are high-strength, case hardened screws with twin-lead, v-notched threads for securely anchoring into concrete, masonry, block and brick. They are available in both a Slotted Hex Washer Head and a Countersunk Flat Head with Phillips drive. The advanced R-Blocker coating offers superior corrosion protection and exceptional test results in salt spray testing. Concrete screws install quickly in a pre-drilled hole of the correct size and can be removed, re-used and reinstalled as necessary. Available in a high strength heat treated steel with Blue R-Blocker finish or 410 Series Stainless Steel with a Silver R-Blocker finish for extreme corrosion protection. The highly corrosion resistant R-Blocker coating is compatible with ACQ treated lumber. Each box includes 100 anchors.