These specially engineered nails are recommended for face and blind nailing many types of fiber cement siding such as Allura? or HardiPlank. The STORMGUARD? double hot-dipped galvanized coating on these nails ensures excellent long-term rust protection. These nails meet the blind and face nail specification for lap siding 8-1/4 in or less. Wider width sidings require blind (roofing) nails.