S-91870A758 5/16"-18 x 2" ASME B18.3 Tamper-Resistant Torx Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with specialized Torx T40 drive requiring matching tools, preventing unauthorized access in secure facilities
• Superior corrosion protection through 18-8 stainless steel construction and passivated surface treatment for extended service life in harsh environments
• Maximum load-bearing capacity with 70,000 psi tensile strength and Rockwell B70 hardness for demanding industrial applications
• Precision thread engagement featuring Class 3A UNC coarse threads ensuring reliable fastening and vibration resistance
• Optimal flush mounting with standard 82° countersink angle and flat head design for smooth surface finishes
• Full-thread coverage along the 2" length provides consistent clamping force across the entire fastener
• Regulatory compliance assurance meeting ASME B18.3 specifications and international environmental standards

Professional Applications & Engineering Value

Engineered for high-security applications where tampering prevention is critical, these flat head screws deliver exceptional performance in public infrastructure, industrial machinery, and electronic enclosures. The 18-8 stainless steel composition combined with passivated finish creates a protective oxide layer that significantly enhances corrosion resistance in moisture-prone environments. The tamper-resistant Torx T40 drive system addresses security concerns while maintaining high torque transmission capabilities. With Class 3A thread fit and UNC coarse threading, these fasteners provide superior vibration resistance and installation efficiency in production environments. The fully threaded design ensures maximum grip length and distributed stress points, making them ideal for applications requiring consistent clamping force across thick materials or assemblies.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread fit tolerance and UNC 5/16"-18 thread specifications. Complies with ASME B18.3 mechanical standards for dimensional accuracy and performance. Meets environmental regulations including RoHS 3 (2015/863/EU) compliance for restricted substances and REACH (EC 1907/2006) standards for chemical safety. Features standard 82° countersink angle for proper seating in matched countersunk holes.