Manufactured with hardened, heat-treated carbon steel, Split drive anchors are available with a flat, countersunk head or a rounded head. There are two sheared, pre-expanded halves at the base of the anchor that is compressed as the anchor are driven into the concrete. The anchor exerts tremendous force on the inside walls of the hole as the two halves continually try to regain their original shape. This positive expansion compensates for poor grade or old concrete. Concrete Split Drive anchors have low “slip” rates and increased vibration resistance.