S-90402A538 1/4"-20 x 5/8" ASME B18.13 Steel Pan Head Phillips Screws with External-Tooth Lock Washer
Steel Pan Head Phillips Screws with External-Tooth Lock Washer
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Washer & Nut
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Enhanced vibration resistance with integrated external-tooth lock washers that maintain secure fastening in high-stress environments
- Superior corrosion protection through zinc-plated steel construction, extending service life in industrial settings
- High-strength performance with 60,000 PSI tensile strength and Rockwell B69 hardness for demanding applications
- Quick installation efficiency featuring UNC coarse threads and No. 3 Phillips drive for rapid assembly
- Reliable thread engagement with Class 2A fit and full threading for consistent clamping force
- Optimized load distribution through pan head design with 0.492" diameter for superior surface contact
- Regulatory compliance assurance meeting ASME B18.13 specifications and environmental standards
Professional Applications & Engineering Value
Engineered for heavy-duty industrial assemblies, these zinc-plated steel rounded head screws solve critical vibration-induced loosening problems in machinery, automotive, and construction applications. The external-tooth lock washer bites into mating surfaces to prevent rotational movement, while the UNC coarse thread spacing ensures rapid installation in thick materials. The combination of 60,000 PSI tensile strength and Rockwell B69 hardness provides exceptional resistance to shear forces and deformation. The zinc plating offers reliable corrosion protection for outdoor equipment and harsh environments, making these Phillips drive screws ideal for maintenance operations where tool accessibility is limited.
Specification Summary & Compliance
This fastener maintains Class 2A thread fit with 1/4"-20 UNC coarse threads and full threading for consistent engagement. Manufacturing follows ASME B18.13 specifications for dimensional accuracy and performance. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, ensuring safe use across regulated industries. The external-tooth lock washer (0.51" OD, 0.028" thickness) provides certified vibration resistance in demanding applications.
