S-91870A270 5/16"-18 x 3/4" ASME B18.3 Tamper-Resistant Torx Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with T40 Torx drive design to prevent unauthorized access in security-sensitive applications
• Superior corrosion resistance from 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Reliable thread engagement through full UNC coarse threading with Class 2A fit ensuring consistent installation and vibration resistance
• High mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for demanding industrial applications
• Optimized flush mounting with standard 82° countersink angle and flat head design for smooth surface finishes
• Regulatory compliance assurance meeting ASME B18.3 specifications while being RoHS 3 and REACH compliant
• Secure fastening performance combining right-hand thread direction with coarse thread spacing for robust mechanical connections

Professional Applications & Engineering Value

Engineered for industrial security applications, these 18-8 stainless steel flat head screws address critical challenges in access control systems, machinery guarding, and public infrastructure. The tamper-resistant T40 Torx drive provides deliberate obstruction against standard tools while maintaining installation efficiency for authorized personnel. The passivated finish enhances the natural corrosion resistance of stainless steel, making these security screws ideal for outdoor installations, marine environments, and chemical processing facilities where environmental degradation compromises fastener integrity. With full UNC coarse threading and Class 2A thread fit, these fasteners ensure rapid installation and reliable performance in vibration-prone equipment, while the 82° countersink angle creates seamless surface transitions in precision assemblies.

Specification Summary & Compliance

This 5/16"-18 x 3/4" flat head screw features precision UNC coarse threading with Class 2A thread fit tolerance for consistent engagement. Manufacturing complies with ASME B18.3 specifications for dimensional accuracy and performance standards. The fastener demonstrates full compliance with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations governing chemical substances, ensuring environmental responsibility and workplace safety in global industrial supply chains.