Simpson Strong Tie S70ACNB 70D Roofing Common Annular Ring Shank Type, Stainless Steel, 7-Inch and 4-Gauge, 25-Pound, 250-Piece 15/32-inch head diameter and .238-inch shank diameter Common Annular Ring Shank Type 304 Stainless Steel Annular Ring increases pull-out resistance Stainless-steel nails are recommended for construction of permanent wood foundations Choose type 316 for seaside applications and superior corrosion resistance