Made with a steel core and coated with high-density plastic, these stakes are strong, durable, and will withstand the very toughest conditions.5/16'' THIN Super Steel Stakes are ready for heavy lifting. Made with a steel core and coated with high-density plastic, these stakes are strong, durable, and will withstand the very toughest conditions. Each stake is uniformly shaped and has ridges that can be used to grab trellis, zip ties, twist tie, soft tie, and other supportive wire/tie.