S-91128A478 1.312" ID Square Washers

Key Features & Benefits at a Glance

• Enhanced Load Distribution - The 4" square shape provides a larger surface area than round washers, reducing surface pressure and preventing material damage in heavy-duty applications.
• Superior Corrosion Resistance - Black-oxide steel finish offers improved protection against rust and oxidation, extending component life in harsh industrial environments.
• Precision Fit for 1 1/4" Screws - The 1.312" inner diameter ensures accurate alignment and secure fastening, minimizing installation errors and improving assembly reliability.
• Exceptional Mechanical Strength - With a Rockwell 15N80 hardness, this washer maintains structural integrity under high stress and vibration, reducing the risk of deformation or failure.
• Regulatory Compliance Assurance - Meets RoHS 3 and REACH standards, ensuring safe use in regulated industries and global market accessibility.
• Durable Long-Term Performance - Consistent thickness range (0.220-0.280") provides reliable spacing and vibration damping, crucial for construction and machinery applications.
• Wide Industrial Compatibility - Designed for inch-system fasteners, it seamlessly integrates with standard North American equipment and replacement part inventories.

Professional Applications & Engineering Value

This square washer addresses critical engineering challenges in heavy-duty industrial settings where standard washers fail. The black-oxide steel construction combats corrosion in outdoor construction, agricultural machinery, and structural steel assemblies, while the 4" width distributes clamping force effectively to prevent joint loosening under dynamic loads. Its Rockwell 15N80 hardness ensures consistent performance in high-vibration environments like conveyor systems and heavy equipment manufacturing. The precise 1.312" ID accommodates 1 1/4" screws perfectly, eliminating misalignment issues during rapid assembly operations. By combining material durability with dimensional accuracy, this washer reduces maintenance frequency and enhances the safety of industrial fastening systems.

Specification Summary & Compliance

This square washer features an inner diameter of 1.312" with a thickness range of 0.220-0.280" and 4" width, manufactured to inch-system standards for compatibility with 1 1/4" screw sizes. It maintains Rockwell 15N80 hardness for consistent mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) under exemption 6(a) for lead in steel alloys and REACH (EC 1907/2006) regulations as of January 2023, ensuring adherence to international environmental and safety standards for industrial components.