S-96551A120 0.332" ID x 0.61" OD ASME B18.21.1; MS35333-75; NASM35333 Mil. Spec. Internal-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with internal teeth that bite into mating surfaces to prevent loosening under dynamic loads
• Exceptional corrosion resistance provided by 410 stainless steel construction for long service life in harsh environments
• Precision dimensional control with 0.332" ID and 0.61" OD ensuring perfect fit for 5/16" fasteners
• Optimized hardness profile at Rockwell C40-50 for durable teeth that maintain locking performance through repeated use
• Industry-standard compliance meeting ASME B18.21.1, MS35333-75, and NASM35333 specifications for reliable performance
• Environmental regulation compliance with RoHS 3 and REACH standards for safe use in regulated industries
• Consistent thickness control between 0.028-0.034" for uniform clamping force distribution

Professional Applications & Engineering Value

This 410 stainless steel internal tooth lock washer delivers critical vibration resistance in demanding industrial applications where fastener security is paramount. The strategically positioned internal teeth create multiple biting points that dig into both the fastener and mating surface, effectively preventing rotational loosening caused by machinery vibration, thermal cycling, or dynamic loading conditions. Engineered to ASME B18.21.1 standards, this precision component maintains reliable locking performance in automotive assemblies, heavy equipment, aerospace components, and industrial machinery where vibration-resistant fastening solutions are essential for operational safety and reduced maintenance intervals. The combination of controlled hardness and stainless steel construction ensures the teeth maintain their biting capability without fracturing, while providing corrosion resistance that extends service life in challenging environments.

Specification Summary & Compliance

This internal tooth lock washer features precise dimensional specifications including 0.332" inner diameter, 0.61" outer diameter, and thickness ranging from 0.028" to 0.034" for optimal performance with 5/16" fasteners. Manufactured to exacting industry standards including ASME B18.21.1, MS35333-75, and NASM35333, ensuring consistent quality and performance. The washer demonstrates full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for use in regulated industries and international markets. With hardness maintained at Rockwell C40-50 and teeth positioned internally, this washer delivers reliable locking performance meeting the most demanding industrial requirements.