S-90416A112 0.168" ID x 0.506" OD ASME B18.21.1 Internal / External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with internal and external teeth that bite into mating surfaces to prevent loosening under dynamic loads
• Enhanced corrosion protection from black-oxide steel finish, extending service life in demanding industrial environments
• Exceptional hardness and durability with Rockwell C40 rating, maintaining tooth integrity and locking performance under high stress
• Precision dimensional control with 0.168" ID and 0.506" OD ensuring perfect fit for No. 8 screws in inch-system assemblies
• Reliable compliance with ASME B18.21.1 specifications, guaranteeing consistent quality and interchangeability
• Environmental responsibility through RoHS 3 and REACH compliance, meeting global regulatory requirements
• Optimized thickness range (0.023-0.027") providing ideal spring tension while accommodating surface variations

Professional Applications & Engineering Value

This heavy-duty tooth lock washer delivers critical vibration-resistant performance in demanding applications where fastener security is paramount. The unique internal/external tooth configuration creates multiple biting points that dig into both the fastener and mating surface, effectively resisting rotational forces in machinery, automotive, and heavy equipment assemblies. Manufactured from black-oxide steel with Rockwell C40 hardness, these washers maintain their locking teeth integrity even under extreme vibration and thermal cycling. The precise dimensional control ensures consistent performance in No. 8 screw applications across industrial maintenance, manufacturing, and construction sectors where reliable fastener retention prevents costly downtime and safety hazards.

Specification Summary & Compliance

This tooth lock washer features precise dimensional specifications including 0.168" internal diameter, 0.506" outer diameter, and thickness range of 0.023-0.027" specifically designed for No. 8 screw applications. Manufactured in compliance with ASME B18.21.1 standards for dimensional accuracy and performance requirements. The product meets RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) regulations (updated to 233 SVHC as of 01/17/2023), ensuring environmental responsibility and global market acceptance.