Used for stitching metal or attaching to metal. A pre-drilled hole is required. Manufactured from A2 Stainless Steel for use where ultimate corrosion resistance. Stainless steel must be used where there is corrosive environment and/or the base material has inherent corrosive characteristics. Countersunk head gives a discreet finish into pre-countersunk holes.Stainless Steel suitable for outdoor applications.60° self-tapping thread for ease of insertion.