Simpson Titen HD screw anchors are self undercutting, non-expansion screw anchors that are designed to be quickly and easily installed. All Titen HD screw anchors feature a patented thread design with serrated cutting teeth for easy installation. The high quality 316 stainless steel these are made out of makes them ideal for installation in areas where corrosion is a problem, such as exterior, salt water or where other corrosive chemicals may be present.