S-90476A112 0.329" ID x 0.875" OD ASME B18.21.1 USS Washers

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc yellow-chromate plating, extending service life in harsh environments
• High-strength performance with Grade 9 classification and Rockwell C43 hardness for demanding applications
• Precise dimensional fit with 0.329" ID and 0.875" OD ensuring proper alignment with 5/16" fasteners
• Superior load distribution thanks to USS flat design and 0.079-0.093" thickness for enhanced joint integrity
• Industry-standard compliance with ASME B18.21.1 specifications for reliable mechanical performance
• Environmental responsibility with full RoHS 3 and REACH compliance for safe industrial usage
• Durable steel construction providing consistent performance under high-stress conditions

Professional Applications & Engineering Value

These Grade 9 USS flat washers deliver critical engineering value through their zinc yellow-chromate plated steel construction, specifically engineered to combat galvanic corrosion and environmental degradation in industrial settings. The Rockwell C43 hardness ensures maintained surface integrity under heavy clamping forces, preventing deformation in high-vibration applications such as heavy machinery, structural steel connections, and automotive assemblies. The precise 5/16" sizing with standardized USS dimensions guarantees proper load distribution across joint surfaces, effectively preventing bolt head embedding and surface damage. This combination of corrosion-resistant properties and mechanical strength makes these washers ideal for outdoor infrastructure, marine equipment, and manufacturing facilities where long-term reliability is paramount.

Specification Summary & Compliance

Manufactured to exact ASME B18.21.1 dimensional standards with precise inner diameter (0.329") and outer diameter (0.875") specifications. The Grade 9 classification ensures high-strength performance characteristics suitable for critical applications. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental safety and regulatory adherence for industrial procurement. The zinc yellow-chromate plating provides superior corrosion protection while maintaining the mechanical properties required for heavy-duty fastening systems.