Flat washers are great for adding resistance to your bolts and screws to prevent them from boring into the wood and weakening it. These Deck Plus SAE fine threaded washers are finished with a black epoxy coating and are designed to fit nuts & bolts of a similar size and finish. This black finish is designed to match the latest trends in black-finished hardware. When selecting a washer, be sure to pick one that matches the fasteners you are already using. Picking a different finish may cause a chemical reaction, weakening your fasteners over time.