S-97775A370 0.32" ID x 0.61" OD ASME B18.21.1; MS35335-62 Mil. Spec. External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with external tooth design that bites into mating surfaces to prevent loosening under dynamic loads
• Exceptional corrosion resistance provided by 410 stainless steel construction for long-term reliability in harsh environments
• Optimized hardness rating of Rockwell C40 ensures teeth maintain their locking grip without deforming under pressure
• Precision dimensional control with ID 0.32" and OD 0.61" ensures perfect fit for 5/16" fasteners in demanding applications
• Dual standard compliance with both ASME B18.21.1 and MS35335-62 specifications guarantees engineering consistency
• Environmental regulation compliance with RoHS 3 and REACH standards for safe use in regulated industries
• Consistent thickness range of 0.028-0.034" provides reliable performance across multiple installation cycles

Professional Applications & Engineering Value

This 5/16" external tooth lock washer delivers critical vibration resistance in demanding mechanical systems where fastener security is paramount. Engineered from 410 stainless steel with Rockwell C40 hardness, the external teeth create multiple biting points that dig into both the fastener head and base material, effectively preventing rotational loosening caused by machinery vibration, thermal cycling, or dynamic loading. The inch system measurement ensures compatibility with standard North American equipment, while the corrosion-resistant properties make it ideal for industrial machinery, automotive assemblies, and outdoor equipment exposed to moisture and chemicals. This heavy-duty lock washer solves the common engineering challenge of maintaining bolt preload in high-vibration environments, reducing maintenance frequency and preventing catastrophic assembly failures.

Specification Summary & Compliance

This external tooth lock washer features precise dimensional specifications including 0.32" ID, 0.61" OD, and thickness range of 0.028-0.034" specifically designed for 5/16" screw size applications. Manufactured to meet ASME B18.21.1 and MS35335-62 standards, ensuring consistent performance and interchangeability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for use in regulated industries and international markets.