S-90069A130 0.318" ID x 0.599" 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 for secure locking
• Enhanced corrosion protection with zinc-plated steel construction for extended service life in demanding environments
• Optimal hardness performance with Rockwell C44 rating ensuring consistent locking force and minimal deformation
• Perfect flush mounting with 82° countersink angle that matches standard screw heads for smooth surface profiles
• Precise dimensional compatibility with 5/16" screws (0.318" ID, 0.599" OD) for reliable fit and function
• Industry-standard compliance meeting ASME B18.21.1 specifications for guaranteed quality and interchangeability
• Environmental regulatory adherence with RoHS 3 and REACH compliance for global manufacturing applications

Professional Applications & Engineering Value

These external tooth lock washers provide critical vibration-resistant fastening solutions for industrial machinery, automotive assemblies, and heavy equipment where secure locking is paramount. The zinc-plated steel construction offers excellent corrosion resistance while maintaining the necessary Rockwell C44 hardness to prevent tooth deformation under load. The 82° countersink angle ensures flush mounting with standard fasteners, eliminating protrusions in precision applications. Engineered to prevent loosening in high-vibration environments, these ASME B18.21.1 compliant washers deliver reliable performance in manufacturing, construction, and maintenance operations where safety and durability are critical concerns.

Specification Summary & Compliance

This countersunk external tooth lock washer features precise dimensions (ID: 0.318", OD: 0.599", Thickness: 0.023-0.028") specifically designed for 5/16" screw applications. Manufactured to ASME B18.21.1 standards with controlled tooth geometry and Rockwell C44 hardness for consistent performance. The product maintains full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and global market acceptance for industrial fastener applications.