The Beckson screw-out deck plate was designed to provide access without the use of tools, with a single start, non-jamming (no cross-thread), extra strong, self-cleaning buttress thread. A self-aligning center and an innovative gasket assure a watertight seal. A unique back-up sealing wall leaves the plate water resistant, even if the gasket is removed. A screw-out plate should be used in compartments where a change in air pressure due to temperature or oil canning can occur. Deck plates are used for access, inspection, and clean out for compartments and tanks, or just as General access for shut-off valves or back fastenings.