Deck Screws are designed for attaching rigid insulation board, single ply membrane, and wood blocking to carbon steel and wood decks. Some sizes can also be used in concrete decks. Available in No. 12 diameter in carbon steel with a Phillips-style head. The Deck Screws are used in conjunction with insulation or membrane plates and can also be used with batten bar.For Corrosion protection the screws are coated with Perma-Seal, a proprietary fluoropolymer, which meets the requirements of Factory Mutual Research Corporation Standard 4470.