S-91128A639 1.938" ID Square Washers

Key Features & Benefits at a Glance

• Enhanced Load Distribution: 3" width provides superior surface coverage, preventing surface damage and loosening under high-stress conditions.
• Superior Corrosion Resistance: Black-oxide steel finish offers reliable protection against rust and wear in harsh industrial environments.
• Precision Fit for Secure Fastening: 1.938" ID ensures accurate alignment with 1 3/4" screws, reducing installation errors and improving joint integrity.
• Exceptional Mechanical Strength: Rockwell 15N80 hardness rating guarantees durability and resistance to deformation under heavy loads.
• Consistent Thickness for Uniform Performance: 0.235-0.265" thickness range maintains reliable pressure distribution across applications.
• Global Compliance Assurance: Meets RoHS 3 and REACH standards, ensuring safe use in regulated markets and environmentally sensitive projects.
• Optimized for Heavy-Duty Applications: Square design and inch-system specifications make it ideal for construction, machinery, and structural assemblies.

Professional Applications & Engineering Value

Engineered for demanding industrial environments, this square washer addresses critical challenges in heavy machinery, structural steel connections, and construction assemblies. The black-oxide steel material provides a durable barrier against moisture and chemical exposure, significantly extending service life in outdoor or corrosive settings. Its generous 3" width and square profile maximize bearing surface area, effectively distributing clamp load to prevent bolt loosening and material crushing—common failures in high-vibration applications. With precise 1.938" ID matching standard 1 3/4" screw sizes, it ensures quick, accurate installation while maintaining Rockwell 15N80 hardness to resist permanent deformation under extreme pressure. This combination of robust material properties and dimensional accuracy makes it an essential component for engineers seeking reliable fastening solutions in infrastructure, manufacturing equipment, and heavy-load bearing structures.

Specification Summary & Compliance

This square washer conforms to inch-system dimensional standards with an inner diameter of 1.938", width of 3", and controlled thickness between 0.235-0.265". Manufactured from black-oxide steel with a Rockwell 15N80 hardness rating, it is designed specifically for use with 1 3/4" screws. The product is fully compliant with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as a steel alloying element and meets REACH (EC 1907/2006) requirements as of January 17, 2023, including 233 SVHC substances, ensuring adherence to international environmental and safety regulations.