S-90484A537 1/4"-20 x 1/2" ASME B18.3, ASTM F835 Tamper-Resistant Hex-Drive Steel Button Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with specialized hex drive design to prevent unauthorized removal in high-security applications
• Superior corrosion protection through black-oxide coating on alloy steel, extending service life in demanding environments
• Exceptional load-bearing capacity with 130,000 psi tensile strength for heavy-duty industrial applications
• Precision thread engagement through Class 3A thread fit ensuring reliable fastening and vibration resistance
• Optimized installation efficiency with UNC coarse threading for faster assembly and reduced cross-threading risks
• Maximum thread contact through full threading along the entire 1/2" length for superior holding power
• Regulatory compliance assurance meeting ASME B18.3, RoHS 3, and REACH standards for quality and environmental safety

Professional Applications & Engineering Value

These black-oxide alloy steel rounded head screws with tamper-resistant hex drive address critical security and durability challenges in industrial settings. The combination of Rockwell C39 hardness and 130,000 psi tensile strength ensures reliable performance in high-stress applications where vibration resistance and long-term structural integrity are paramount. The UNC coarse thread spacing facilitates quick installation while minimizing thread damage, particularly beneficial in production environments requiring rapid assembly. The black-oxide surface treatment provides essential corrosion protection for machinery, electrical enclosures, and outdoor equipment, while the tamper-resistant design secures public infrastructure, transportation systems, and sensitive installations against unauthorized access. These fully threaded screws deliver consistent clamping force across the entire fastener length, making them ideal for critical joints in manufacturing equipment, industrial automation, and security systems.

Specification Summary & Compliance

This fastener features precision 1/4"-20 UNC threads with Class 3A thread fit for superior dimensional accuracy and engagement. Manufacturing complies with ASME B18.3 specifications (ASTM F835) ensuring consistent quality and performance. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, confirming adherence to current environmental regulations for hazardous substances. The combination of fully threaded design, coarse thread spacing, and 0.437" head diameter provides optimal fastening characteristics for industrial applications requiring security, durability, and regulatory compliance.