S-90069A136 0.383" ID x 0.765" OD ASME B18.21.1 Countersunk External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with external teeth that bite into mating surfaces, preventing loosening under dynamic loads
• Enhanced corrosion protection through zinc-plated steel construction, extending service life in demanding environments
• Perfect flush mounting with 82° countersink angle, ensuring smooth surface finishes in countersunk applications
• Exceptional durability with Rockwell C44 hardness, maintaining tooth integrity and locking performance under high stress
• Precision dimensional control with 0.383" ID and 0.765" OD, ensuring proper fit for 3/8" fasteners
• Industry-standard compliance meeting ASME B18.21.1 specifications for reliable performance in critical applications
• Environmental responsibility with RoHS 3 and REACH compliance, safe for use in regulated industries

Professional Applications & Engineering Value

These countersunk external tooth lock washers deliver critical vibration resistance in industrial assemblies where secure fastening is paramount. The zinc-plated steel construction provides excellent corrosion resistance while maintaining the necessary Rockwell C44 hardness to prevent tooth deformation under load. The precisely engineered 82° countersink angle ensures seamless integration with countersunk fasteners, eliminating protrusions that could compromise assembly integrity. Particularly valuable in heavy machinery, automotive, and construction equipment, these washers solve the persistent challenge of fastener loosening caused by vibration and thermal cycling. The external tooth configuration maximizes surface contact area, distributing clamping force evenly while creating positive locking action that maintains joint integrity throughout the product lifecycle.

Specification Summary & Compliance

This precision countersunk external tooth lock washer features dimensional accuracy with 0.383" internal diameter, 0.765" outer diameter, and thickness ranging from 0.028" to 0.034" for consistent performance. Manufactured to ASME B18.21.1 standards, these washers ensure reliable dimensional and mechanical properties. The product maintains full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting current environmental standards for industrial components. Designed specifically for 3/8" fasteners, these washers deliver predictable performance in critical assembly applications requiring verified material properties and dimensional precision.