S-90416A118 0.512" ID x 1.26" OD ASME B18.21.1 Internal / External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance prevents fastener loosening in high-stress applications, ensuring long-term assembly integrity.
• Dual internal and external teeth provide maximum bite and locking force on both the bolt and the mating surface for a secure hold.
• Black-oxide steel construction offers excellent corrosion resistance, extending the washer's service life in demanding environments.
• High Rockwell C40 hardness ensures exceptional durability and resistance to deformation under heavy loads.
• Precision sizing (0.512" ID, 1.26" OD) guarantees a perfect fit for 1/2" screws, facilitating easy and reliable installation.
• Compliance with ASME B18.21.1 standards assures consistent quality, dimensional accuracy, and reliable performance.
• RoHS 3 and REACH compliance makes this washer safe for use in regulated industries and environmentally conscious supply chains.

Professional Applications & Engineering Value

This 1/2" tooth lock washer is engineered to solve the critical industrial problem of joint failure due to vibration and dynamic loads. Its black-oxide steel material provides a robust barrier against rust, making it ideal for automotive, machinery, and construction applications where exposure to harsh conditions is common. The unique internal/external teeth design ensures a powerful, multi-point grip that significantly reduces the risk of fastener back-off, maintaining clamp load in critical assemblies. Manufactured to ASME B18.21.1 specifications, it delivers reliable performance in heavy-duty bolted connections, from industrial equipment to structural frameworks, ensuring operational safety and reducing maintenance downtime.

Specification Summary & Compliance

This washer features precise dimensions with an Inside Diameter of 0.512", Outside Diameter of 1.26", and Thickness of 0.048-0.052", designed for a 1/2" screw size. It conforms to the ASME B18.21.1 standard for tooth lock washers, ensuring dimensional accuracy and mechanical performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally regulated and global industrial markets.