S-91138A920 0.125" ID x 0.313" OD ASME B18.21.1 Plastic Washers

Key Features & Benefits at a Glance

• Exceptional temperature resistance maintains structural integrity from -30°F to 450°F for reliable performance in extreme thermal environments
• Superior hardness rating with Rockwell M114 ensures excellent wear resistance and long service life under mechanical stress
• Precision dimensional control with 0.125" ID and 0.313" OD provides perfect fitment for No. 4 screws in inch-system applications
• Industry-standard compliance with ASME B18.21.1 specifications guarantees consistent quality and interchangeability
• Chemical and environmental resistance of Ultem PEI plastic prevents degradation in harsh operating conditions
• Regulatory compliance assurance with RoHS 3 and REACH standards for use in regulated industries
• Optimized thickness range of 0.025-0.040" allows for proper load distribution while maintaining space efficiency

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these Ultem PEI plastic flat washers solve critical challenges in high-temperature applications where metal components would fail. The polyetherimide material delivers outstanding thermal stability while maintaining excellent mechanical properties across extreme temperature fluctuations from -30°F to 450°F. This makes them ideal for aerospace components, electrical insulation applications, and chemical processing equipment where thermal cycling and chemical exposure are common. The precise 0.125" inner diameter ensures secure seating on No. 4 screws, while the 0.313" outer diameter provides optimal surface coverage for load distribution. These industrial washers eliminate galvanic corrosion concerns when used with dissimilar metals and offer excellent dielectric properties for electrical isolation in electronic assemblies.

Specification Summary & Compliance

This flat washer features precise dimensional specifications with 0.125" inner diameter, 0.313" outer diameter, and thickness ranging from 0.025" to 0.040" manufactured to ASME B18.21.1 standards for consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) regulations and meets REACH (EC 1907/2006) requirements, including the latest SVHC updates as of January 17, 2022. Manufactured from high-performance Ultem PEI plastic with Rockwell M114 hardness rating, these washers are designed for inch-system applications and maintain dimensional stability across the specified temperature range.