S-90476A114 0.521" ID x 1.375" OD ASME B18.21.1 USS Washers

Key Features & Benefits at a Glance

• Exceptional Load Distribution - The 1.375" outer diameter provides a wide bearing surface, effectively spreading the load to prevent surface damage and joint loosening.
• Superior Corrosion Resistance - The zinc yellow-chromate plating on steel offers excellent protection against rust and corrosion, extending the service life in harsh environments.
• High-Strength Reliability - As a Grade 9 fastener component with a Rockwell C43 hardness, this washer maintains integrity under high-stress and heavy-duty applications.
• Precision Fit for 1/2" Fasteners - The 0.521" inner diameter ensures a precise and secure fit on 1/2" screws and bolts, minimizing play and vibration.
• Rigorous Standard Compliance - Manufactured to meet ASME B18.21.1 specifications, guaranteeing dimensional accuracy, consistency, and interchangeability.
• Environmental and Safety Assurance - Compliant with RoHS 3 and REACH regulations, ensuring they are free from hazardous substances for safe use in various industries.
• Durable Construction - A thickness range of 0.122" to 0.146" provides the necessary rigidity and durability to withstand repeated loading without deformation.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these USS flat washers address critical challenges in machinery assembly, structural steelwork, and heavy equipment. The zinc yellow-chromate plated steel construction is key to solving corrosion-related failures, offering a robust barrier against moisture and chemicals. This is vital for outdoor infrastructure, marine environments, and manufacturing plants where component longevity is paramount. The high-strength Grade 9 classification and Rockwell C43 hardness ensure that the washer does not compress or fail under extreme bolt tension, preventing joint relaxation and maintaining clamp load integrity in heavy-duty bolted connections. By providing reliable load distribution and corrosion protection, these washers reduce maintenance frequency and enhance the safety and durability of the overall assembly.

Specification Summary & Compliance

This washer conforms to the dimensional and mechanical requirements of the ASME B18.21.1 standard for inch-series flat washers. Key specifications include an Inner Diameter of 0.521", Outer Diameter of 1.375", and a Thickness range of 0.122" to 0.146", designed for use with 1/2" screw sizes. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its adherence to strict environmental and safety standards for hazardous substances.