S-91138A834 0.281" ID x 0.625" OD ASME B18.21.1 Plastic Washers

Key Features & Benefits at a Glance

• Exceptional thermal stability with a wide operating range from -30°F to 450°F, ensuring reliable performance in extreme temperature environments.
• Superior mechanical strength provided by Ultem PEI plastic and Rockwell M114 hardness, offering excellent resistance to deformation under load.
• Precision dimensional fit with 0.281" ID and 0.625" OD designed for 1/4" screws, ensuring secure fastening and reduced assembly errors.
• Compliance with industry standards including ASME B18.21.1, guaranteeing consistent quality and interchangeability in industrial applications.
• Environmental and safety adherence through RoHS 3 and REACH compliance, making it safe for use in regulated industries.
• Chemical and corrosion resistance inherent to Ultem PEI material, prolonging washer life in harsh or corrosive settings.
• Lightweight and non-conductive properties ideal for electrical insulation and reducing overall assembly weight without sacrificing durability.

Professional Applications & Engineering Value

This Ultem PEI plastic flat washer is engineered to address critical challenges in high-stress industrial environments. Its high-temperature resistance up to 450°F makes it suitable for applications in aerospace, automotive, and electronics, where thermal cycling can cause metal washers to fail. The black Ultem PEI material provides inherent chemical resistance, reducing degradation from oils, solvents, and other harsh substances. With a precision inch-system design and compliance with ASME B18.21.1, it ensures reliable performance in fastening assemblies for machinery, enclosures, and structural components, minimizing downtime and maintenance costs. The flat washer style evenly distributes load, preventing surface damage and enhancing the longevity of connected parts.

Specification Summary & Compliance

This washer features an inner diameter of 0.281", outer diameter of 0.625", and thickness ranging from 0.040" to 0.080", designed for use with 1/4" screws in inch-based systems. It conforms to ASME B18.21.1 specifications for dimensional accuracy and performance. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets stringent environmental and safety regulations for hazardous substances.