S-90900A012 0.195" ID x 0.354" OD ASME B18.21.1 Countersunk External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with external teeth that bite into mating surfaces, preventing loosening under dynamic loads
• Enhanced corrosion resistance from 400 Series Stainless Steel construction for long-term reliability in harsh environments
• Optimized flush mounting with 82° countersink angle ensuring secure, flat-surface installation with No. 10 screws
• Exceptional mechanical durability thanks to Rockwell C34 hardness maintaining tooth integrity under repeated stress
• Guaranteed dimensional precision with 0.195" ID and 0.354" OD meeting strict ASME B18.21.1 specifications
• Regulatory compliance assurance with RoHS 3 and REACH compliance for safe, unrestricted global industrial use
• Consistent performance through controlled 0.020-0.025" thickness ensuring uniform clamping force distribution

Professional Applications & Engineering Value

These No. 10 external tooth lock washers deliver critical vibration-damping performance in demanding industrial applications where fastener security is paramount. The 400 Series Stainless Steel construction provides excellent corrosion resistance for machinery exposed to moisture, chemicals, or outdoor elements. The 82° countersink angle enables flush mounting in precision assemblies while the external teeth create positive locking action that prevents rotational loosening in vibrating equipment, automotive systems, and heavy machinery. Engineered to ASME B18.21.1 standards, these washers maintain consistent performance in high-cycle applications where traditional flat washers fail, reducing maintenance frequency and preventing costly downtime from fastener failure.

Specification Summary & Compliance

This countersunk external tooth lock washer features precise dimensional specifications including 0.195" internal diameter, 0.354" outer diameter, and 0.020-0.025" thickness range. Manufactured to exacting ASME B18.21.1 standards for tooth lock washers, it ensures proper fit and function with No. 10 screws. The washer is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting current substance restriction requirements for industrial components. Material certification confirms 400 Series Stainless Steel composition with Rockwell C34 hardness verification.