S-90474A112 0.344" ID x 0.625" OD ASME B18.21.1 ASME Washers

Key Features & Benefits at a Glance

• Exceptional Load Distribution: The 0.625" OD and 0.344" ID provide a wide bearing surface, effectively distributing load and preventing surface damage to assembled materials.
• Superior Corrosion Resistance: Zinc yellow-chromate plating offers excellent protection against rust and environmental degradation, extending the washer's service life in harsh conditions.
• High-Strength Reliability: Manufactured from Grade 8 steel with a Rockwell C38 hardness, this washer maintains integrity under high stress and vibration, reducing the risk of fastener failure.
• Precision Fit for 5/16" Fasteners: The precise internal diameter ensures a perfect fit with 5/16" screws, facilitating easier assembly and improving joint stability.
• Industry Standard Compliance: Conforms to ASME B18.21.1 specifications, guaranteeing dimensional accuracy and performance consistency for professional applications.
• Environmental & Safety Compliance: Meets RoHS 3 and REACH regulations, ensuring the washer is free from hazardous substances and safe for use in regulated industries.
• Durable & Consistent Performance: The controlled thickness range (0.056-0.071") and robust material provide reliable, repeatable performance in heavy-duty mechanical and structural assemblies.

Professional Applications & Engineering Value

These Grade 8 flat washers are engineered to solve critical challenges in demanding industrial environments. The zinc yellow-chromate plated steel construction combats corrosion, making them ideal for outdoor machinery, automotive assemblies, and construction equipment exposed to moisture and chemicals. Their high strength and hardness (Rockwell C38) prevent deformation under heavy loads, ensuring lasting bolt tension and reducing maintenance needs in high-vibration applications like heavy machinery and structural frameworks. By distributing clamping force evenly, they protect soft materials from damage and prevent loosening, enhancing the safety and longevity of 5/16" fastener systems. This combination of material durability and precision engineering delivers reliable performance in industrial washers applications where failure is not an option.

Specification Summary & Compliance

This washer adheres to strict dimensional standards per ASME B18.21.1, ensuring precise fit and function with inch-system fasteners. Key specifications include an ID of 0.344", OD of 0.625", and thickness between 0.056-0.071", designed for screw size 5/16". The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from restricted hazardous substances and safe for industrial and international use.