S-99435A500 4.1 mm ID x 9 mm OD Finishing Washers

Key Features & Benefits at a Glance

• Superior corrosion resistance from nickel-plated brass construction, ensuring long-term reliability in humid or demanding environments
• Perfect flush mounting with precise 90° countersink angle that eliminates protrusions for smooth, aerodynamic surfaces
• Precision M3 compatibility with 4.1mm ID providing secure fit while preventing thread damage during installation
• Enhanced load distribution through 9mm OD design that reduces surface pressure and material stress
• Environmental compliance assurance with RoHS 3 certification for use in sensitive electronic and industrial applications
• Excellent electrical conductivity inherent to brass material, ideal for grounding and electrical assembly applications
• Consistent dimensional accuracy maintaining tight tolerances for repeatable performance in automated assembly processes

Professional Applications & Engineering Value

These nickel-plated brass countersunk washers solve critical engineering challenges where both corrosion resistance and electrical properties matter. The 90° countersink angle ensures perfectly flush installations in precision equipment, aerospace components, and consumer electronics where surface protrusions compromise functionality or safety. The brass core with nickel plating provides dual protection against galvanic corrosion when mating with dissimilar metals, while maintaining conductivity for grounding applications. Particularly valuable in electronic hardware assemblies and metric fastening systems, these washers prevent loosening from vibration and distribute load effectively across fragile substrates like PCBs and thin metal housings. The combination of material properties and precise M3 sizing makes them ideal for applications demanding both technical performance and regulatory compliance.

Specification Summary & Compliance

Manufactured to precise metric dimensions with 4.1mm internal diameter and 9mm outer diameter, these countersunk washers feature standard 90° countersink angle for compatibility with corresponding screw heads. The nickel-plated brass construction provides consistent dimensional stability and corrosion protection. Product complies with RoHS 3 (2015/863/EU) regulations, ensuring restriction of hazardous substances for electronic and industrial applications. The 1.8mm overall height maintains low profile while providing adequate bearing surface for secure fastening.