#9-15 stainless steel metal to wood screws are sealing self-piercing tapping screws made from type 316 passivated stainless steel for roofing and siding applications in corrosive environments. 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 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.