S-90900A030 0.255" ID x 0.454" OD ASME B18.21.1 Countersunk External-Tooth Lock Washers
Countersunk External-Tooth Lock Washers
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Basic Information
Dimension Parameters
Material & Strength Parameters
Installation & Application Parameters
Finish & Compliance Parameters
Geometric Parameters
Special Type Parameters
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Key Features & Benefits at a Glance
- Superior vibration resistance through external tooth design that bites into mating surfaces to prevent loosening under dynamic loads
- Enhanced durability in harsh environments with 400 Series Stainless Steel construction offering excellent corrosion resistance
- Optimized countersunk seating with 82° angle for flush mounting in precision applications
- Consistent performance under load thanks to Rockwell C34 hardness maintaining tooth integrity
- Reliable dimensional precision with 0.255" ID and 0.454" OD ensuring proper fit for 1/4" fasteners
- Industry-standard compliance meeting ASME B18.21.1 specifications for quality assurance
- Environmental regulation adherence with RoHS 3 and REACH compliance for global manufacturing applications
Professional Applications & Engineering Value
This external tooth lock washer delivers critical vibration resistance in demanding industrial applications where fastener security is paramount. The 400 Series Stainless Steel construction provides exceptional corrosion resistance for harsh environments, while the 82° countersunk angle ensures flush mounting in precision assemblies. The external tooth configuration creates positive locking action by biting into both the fastener head and bearing surface, effectively preventing rotational loosening caused by vibration or thermal cycling. Engineered with Rockwell C34 hardness, these washers maintain tooth integrity under repeated loading cycles, making them ideal for machinery, automotive, and heavy equipment applications where reliability cannot be compromised.
Specification Summary & Compliance
This countersunk tooth lock washer features precise dimensions of 0.255" ID, 0.454" OD, and 0.020-0.025" thickness, designed specifically for 1/4" fasteners. Manufactured to ASME B18.21.1 standards, it ensures consistent performance and interchangeability. The washer is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting the latest environmental requirements for industrial components.
