S-91133A155 0.688" ID Square Washers

Key Features & Benefits at a Glance

• Superior corrosion protection with galvanized steel construction for extended service life in harsh industrial environments
• Exceptional load distribution from the 4" square design, preventing surface damage and maintaining structural integrity
• Precise fitment with 0.688" inner diameter specifically engineered for 5/8" screw applications
• Enhanced durability with Rockwell B40 hardness rating, resisting deformation under heavy loads
• Consistent performance maintained through controlled thickness range of 0.235-0.265"
• Environmental compliance meeting RoHS 3 and REACH standards for responsible manufacturing
• Versatile industrial application suitable for construction, mechanical assemblies, and heavy machinery

Professional Applications & Engineering Value

This heavy-duty square washer addresses critical engineering challenges in industrial fastening systems. The galvanized steel construction provides exceptional corrosion resistance, making it ideal for outdoor construction, machinery assemblies, and marine applications where environmental exposure compromises fastener integrity. The square profile offers superior load distribution compared to round washers, preventing embedding in softer materials and maintaining clamping force in high-vibration environments. With precise 0.688" inner diameter matching standard 5/8" screw sizes, this washer ensures proper alignment and prevents bolt hole obstruction. The Rockwell B40 hardness maintains dimensional stability under extreme pressure, while the zinc coating creates a sacrificial layer that extends service life in corrosive conditions common in industrial and construction settings.

Specification Summary & Compliance

This inch-system square washer features precise dimensional specifications including 0.688" inner diameter, 4" width, and thickness range of 0.235-0.265". Manufactured from galvanized steel with Rockwell B40 hardness rating, the product complies with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as an alloying element in steel and meets REACH (EC 1907/2006) compliance standards as of January 17, 2023, addressing 233 Substances of Very High Concern. The washer is engineered for heavy-duty industrial applications requiring reliable performance and environmental regulatory compliance.