Metal to wood screws are self-piercing, sealing tapping screws made from heat treated C1022 steel; case hardened for roofing and siding applications. Features a 1/4″ across flat high hat hex washer head with assembled EPDM (Ethylene Propylene Diene Monomer) washer, offers easy driving and conforms to the 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 pull out. All screws are 1,000 hour salt spray test dacro-coated. The color screws are powder-coated over the dacro base coating. Screws are packed 250 pieces.