Standard Flat Washers are general-purpose washers used to distribute load and protect surfaces in everyday bolting applications. Available in common USS and SAE patterns, these washers come in a variety of materials and finishes and are typically non-hardened, making them suitable for light to medium-duty fastening. Structural Washers, by contrast, are hardened washers manufactured to ASTM F436 for high-strength bolting assemblies, providing the durability and load-bearing performance required for structural steel, anchors, and other critical connections. Also available in Stainless Steel.