Paulin Roofing Electro Galvanized Nails are large flat thin head nails with a short body. They are used for attaching asphalt, fibreglass shingles or sheet metal to wood. Shanks are smooth or ringed for increased pull-out strength. When installing roofing nails be sure to flush to the shingles. Avoid countersinking roofing nails as this can cause shingles to tear. Thin coating of Electro Galvanized zinc prevents rusting and withstands occaisonal moisture; however, it is less robust than Hot Galvanized and should not be exposed to weather if used correctly. Not suitable for exterior applications.