S-90108A031 0.438" ID x 1" OD ASME B18.21.1 USS Washers

Key Features & Benefits at a Glance

• Superior corrosion protection with zinc-plated steel construction for extended service life in demanding environments
• Optimal load distribution with 1" outer diameter preventing surface damage and maintaining joint integrity
• Precision fit for 3/8" fasteners with 0.438" inner diameter ensuring secure installation and vibration resistance
• Heavy-duty performance meeting USS standards for industrial-grade applications requiring reliable load bearing
• Regulatory compliance assurance with RoHS 3 and REACH adherence for global supply chain compatibility
• Dimensional consistency manufactured to ASME B18.21.1 specifications for reliable interchangeability
• Versatile thickness range (0.064"-0.104") accommodating various assembly requirements and compression needs

Professional Applications & Engineering Value

These USS flat washers deliver critical engineering solutions where load distribution and corrosion resistance are paramount. The zinc-plated steel construction provides sacrificial protection against environmental degradation, significantly extending service life in outdoor equipment, structural assemblies, and machinery exposed to moisture. With precise 3/8" screw size compatibility and ASME B18.21.1 dimensional conformity, these flat washers prevent bolt head embedding, reduce friction during tightening, and maintain clamping force in vibrating environments. The 1" OD creates an optimal bearing surface that protects soft materials while the controlled thickness range ensures consistent performance across production runs, making them ideal for industrial maintenance, construction projects, and manufacturing applications requiring reliable fastener systems.

Specification Summary & Compliance

Manufactured to ASME B18.21.1 dimensional standards with 0.438" inner diameter and 1" outer diameter. Constructed from zinc-plated steel with thickness ranging 0.064"-0.104" for 3/8" screw applications. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and global market acceptance. These USS pattern washers provide reliable performance in general engineering applications where standardized dimensions and corrosion protection are required.