#9-15 Metal-to-wood screws are sealing self-piercing tapping screws made from heat treated C1022 steel, case hardened for roofing and siding applications. A 1/4 in across flats high hat hex washer head with assembled EPDM washer offers easy driving and conforms to the metal surface for a secure and long-lasting seal. The twin lead type 17 point and hi-lo threads offer faster drive time and greater resistance to pullout. All screws are 1000 hr salt spray test dacro-coated. Colored screws are powder-coated over the dacro base coating. All Acorn International screws are packed 250 pieces in a heavy-duty tear-off resealable bag, UPC-coded and retail ready. All bag and carton labels are trilingual. Cartons are heavy-duty cardboard of uniform size and distinctive yellow color for better retail identity.