S-94744A163 0.125" ID x 0.438" OD ASME B18.21.1 ASME Washers

Key Features & Benefits at a Glance

• Enhanced Corrosion Resistance: Zinc-plated steel construction provides reliable protection against rust and environmental degradation, extending service life in demanding industrial settings.
• Precision Fit for No. 4 Screws: The 0.125" inner diameter ensures a secure and accurate fit, preventing misalignment and improving assembly efficiency.
• Optimized Load Distribution: With a 0.438" outer diameter, this washer effectively spreads clamping force, reducing surface damage and maintaining joint integrity.
• Consistent Durability: Rockwell B40 hardness offers a robust balance of strength and ductility, resisting deformation under pressure for long-term reliability.
• Guaranteed Standard Compliance: Manufactured to ASME B18.21.1 specifications, ensuring dimensional accuracy, interchangeability, and performance predictability.
• Environmental & Regulatory Safety: Compliant with RoHS 3 and REACH regulations, making it suitable for global supply chains and environmentally conscious applications.
• Uniform Thickness Control: Thickness maintained between 0.036" and 0.045" ensures consistent performance and reliable sealing or spacing in assemblies.

Professional Applications & Engineering Value

This zinc-plated steel flat washer is engineered to address common challenges in industrial fastening, such as galvanic corrosion, joint loosening, and surface marring. The zinc plating acts as a sacrificial layer, significantly enhancing corrosion resistance in humid or chemically exposed environments, which is critical for outdoor machinery, automotive assemblies, and electrical enclosures. Its precise 0.125" ID and 0.438" OD dimensions, compliant with ASME B18.21.1, ensure optimal load distribution when used with No. 4 screws, preventing stress concentration on soft materials and reducing the risk of fastener failure. The Rockwell B40 hardness provides sufficient toughness to withstand vibrational forces without cracking, making it ideal for applications in manufacturing, construction, and maintenance where reliability and longevity are paramount.

Specification Summary & Compliance

This flat washer meets ASME B18.21.1 dimensional and mechanical standards, ensuring precise fit and function. Key specifications include an inner diameter of 0.125", outer diameter of 0.438", and thickness range of 0.036" to 0.045". It is manufactured from zinc-plated steel with a hardness of Rockwell B40. 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, confirming its suitability for restricted substance-controlled applications.