S-90900A009 0.167" ID x 0.322" OD ASME B18.21.1 Countersunk External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance through external tooth design that bites into mating surfaces, preventing fastener loosening in high-stress applications
• Enhanced corrosion protection with 400 Series Stainless Steel construction, ideal for harsh industrial environments
• Optimized flush mounting with 82° countersink angle that ensures smooth surface alignment with countersunk screw heads
• Consistent performance reliability backed by Rockwell C34 hardness for durable, long-lasting locking capability
• Precise No. 8 screw compatibility with 0.167" ID and 0.322" OD dimensions for accurate fit and secure fastening
• Industry-standard compliance meeting ASME B18.21.1 specifications for quality assurance in critical applications
• Environmental regulation adherence with full RoHS 3 and REACH compliance for global market acceptance

Professional Applications & Engineering Value

This 400 Series Stainless Steel External Tooth Lock Washer delivers exceptional engineering value in applications where vibration-induced loosening compromises assembly integrity. The external tooth configuration creates multiple biting points that dig into both the fastener and workpiece, maintaining clamp force under dynamic loads. The countersunk design with 82° angle provides flush surface mounting while the Rockwell C34 hardness ensures teeth maintain their biting capability through repeated stress cycles. Particularly effective in industrial machinery, automotive assemblies, and electrical enclosures, this washer solves the critical challenge of maintaining fastener tension in high-vibration environments while offering the corrosion resistance needed for extended service life in demanding conditions.

Specification Summary & Compliance

This external tooth lock washer features precise dimensional specifications including 0.167" internal diameter, 0.322" outer diameter, and thickness ranging 0.017-0.021". Manufactured to ASME B18.21.1 standards for quality assurance, the washer maintains dimensional accuracy and performance consistency. The product is fully compliant with RoHS 3 (2015/863/EU) regulations and REACH (EC 1907/2006) requirements, including the latest SVHC updates as of June 14, 2023. These compliance certifications ensure the washer meets international environmental and safety standards for global industrial applications.