S-98438A240 0.256" ID x 0.51" OD ASME B18.21.1 External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with external teeth that bite into mating surfaces to prevent loosening under dynamic loads
• Exceptional corrosion resistance provided by 400 Series Stainless Steel construction for long-term reliability in harsh environments
• Optimized hardness performance with Rockwell C34 rating ensuring consistent tooth engagement without material deformation
• Industry-standard compliance meeting ASME B18.21.1 specifications for dimensional accuracy and functional reliability
• Environmental regulation adherence with full RoHS 3 and REACH compliance for global manufacturing applications
• Precision dimensional fit featuring 0.256" ID and 0.51" OD for perfect alignment with 1/4" fasteners
• Reduced maintenance requirements through durable construction that maintains locking performance through multiple installation cycles

Professional Applications & Engineering Value

This external tooth lock washer delivers critical vibration-resistant fastening solutions for demanding industrial applications where joint integrity is paramount. The 400 Series Stainless Steel construction provides excellent corrosion resistance while maintaining the necessary Rockwell C34 hardness for reliable tooth engagement. Engineered to ASME B18.21.1 standards, these washers effectively prevent fastener loosening in heavy machinery, automotive assemblies, and electrical equipment subjected to constant vibration and thermal cycling. The external tooth configuration ensures maximum biting action into both the fastener head and mating surface, creating a secure mechanical lock that outperforms standard flat washers in high-vibration environments. With precise 0.256" ID and 0.51" OD dimensions, these washers provide perfect fitment for 1/4" fasteners while the tooth design accommodates minor surface irregularities for consistent performance across production runs.

Specification Summary & Compliance

This external tooth lock washer features precise dimensional specifications including 0.256" internal diameter, 0.51" outer diameter, and thickness ranging from 0.023" to 0.028". Manufactured to ASME B18.21.1 standards with Rockwell C34 hardness certification, the washer ensures consistent performance in inch system applications. The product maintains full compliance with RoHS 3 (2015/863/EU) regulations and REACH (EC 1907/2006) requirements current through June 14, 2023, addressing 235 Substances of Very High Concern for environmentally conscious manufacturing operations.