S-90416A116 0.384" ID x 0.985" OD ASME B18.21.1 Internal / External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance through internal and external teeth design that bite into mating surfaces, preventing loosening under dynamic loads
• Enhanced durability with Rockwell C40 hardness rating, maintaining tooth integrity and locking performance through repeated use cycles
• Corrosion-resistant black-oxide steel construction providing protection against rust and extending service life in demanding industrial environments
• Precision dimensional control with 0.384" ID and 0.985" OD ensuring perfect fit for 3/8" screw applications and consistent installation
• Industry-standard compliance with ASME B18.21.1 specifications, guaranteeing interchangeability and reliable performance across applications
• Environmental regulation adherence with RoHS 3 and REACH compliance, making them suitable for global supply chains and regulated industries
• Optimized thickness range (0.037-0.041") providing sufficient spring action while maintaining compact installation profile

Professional Applications & Engineering Value

This black-oxide steel tooth lock washer delivers exceptional engineering value in applications where vibration-induced fastener failure poses significant risks. The unique internal/external tooth configuration creates multiple biting points that dig into both the fastener head and mounting surface, effectively resisting rotational forces that cause conventional washers to fail. Manufactured to ASME B18.21.1 standards, these washers provide reliable performance in heavy machinery, automotive assemblies, and industrial equipment where constant motion and shock loads are prevalent. The Rockwell C40 hardness ensures teeth maintain their sharp biting edges through repeated torque cycles, while the black-oxide coating offers corrosion protection in environments exposed to moisture and chemicals. For 3/8" screw applications in construction, manufacturing, and transportation sectors, this washer eliminates the need for additional locking mechanisms, streamlining assembly while enhancing safety.

Specification Summary & Compliance

This precision tooth lock washer features dimensional specifications of 0.384" inner diameter, 0.985" outer diameter, and thickness ranging from 0.037" to 0.041", engineered specifically for 3/8" screw applications. Manufactured in compliance with ASME B18.21.1 standards for tooth lock washers, ensuring consistent quality and performance. The product meets RoHS 3 (2015/863/EU) compliance for restricted hazardous substances and REACH (EC 1907/2006) compliance with the latest SVHC list (updated 01/17/2023, 233 substances), making it suitable for international markets and environmentally conscious applications.