S-91128A465 1.312" ID Square Washers

Key Features & Benefits at a Glance

• Enhanced Load Distribution – The large 3" square shape provides superior surface coverage, reducing pressure points and preventing material damage in heavy-duty applications.
• Superior Corrosion Resistance – The black-oxide steel finish offers excellent protection against rust and wear, extending the washer's service life in harsh industrial environments.
• Precision Fit for Secure Fastening – With a 1.312" inner diameter, this washer ensures a perfect match for 1 1/4" screws, minimizing loosening and improving assembly reliability.
• Exceptional Mechanical Strength – A Rockwell 15N80 hardness rating and 0.235-0.265" thickness deliver high durability and resistance to deformation under heavy loads.
• Regulatory Compliance for Global Use – Meets RoHS 3 and REACH standards, ensuring safety and environmental responsibility for international supply chains.
• Consistent Dimensional Accuracy – Manufactured to precise inch system specifications, guaranteeing reliable performance and interchangeability in machinery and structural assemblies.

Professional Applications & Engineering Value

This heavy-duty square washer is engineered to address critical challenges in industrial fastening, such as joint failure and surface indentation. The black-oxide steel construction provides a robust barrier against corrosion, making it ideal for outdoor equipment, construction frameworks, and machinery exposed to moisture or chemicals. Its generous 3" width and substantial thickness effectively distribute clamping force, protecting softer materials from damage and maintaining bolt preload in high-vibration settings like automotive or structural steel connections. By specifying this square washer for 1 1/4" screw applications, engineers achieve longer service intervals and reduced maintenance costs, supported by its compliance with major environmental regulations.

Specification Summary & Compliance

This square washer features an inner diameter of 1.312", a width of 3", and a thickness range of 0.235-0.265", designed for use with 1 1/4" screws in inch-based systems. It is manufactured from black-oxide steel with a hardness of Rockwell 15N80 to ensure dimensional stability and strength. 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, affirming its suitability for rigorous industrial and international markets.