S-91870A250 1/4"-20 x 5/8" ASME B18.3 Tamper-Resistant Torx Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with T30 Torx drive prevents unauthorized access in secure environments
• Superior corrosion protection through 18-8 stainless steel construction and passivated finish for extended service life
• High-load capacity with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Optimized flush mounting with standard 82° countersink angle and flat head design for smooth surface finishes
• Reliable thread engagement through full UNC coarse threading and Class 2A fit for consistent fastening performance
• Industry compliance assurance meeting ASME B18.3 specifications and environmental regulations (RoHS 3, REACH)
• Secure drive transmission with tamper-resistant Torx design that withstands high torque applications

Professional Applications & Engineering Value

This 18-8 stainless steel flat head screw addresses critical challenges in industrial fastening where security, corrosion resistance, and structural integrity are paramount. The tamper-resistant T30 Torx drive provides superior anti-vandalism protection for public infrastructure, electrical enclosures, and machinery requiring restricted access. The combination of passivated finish and stainless steel material ensures exceptional performance in corrosive environments, from marine applications to chemical processing equipment. With full UNC coarse threading and Class 2A thread fit, these screws deliver reliable installation in various materials while the 82° countersink angle creates seamless surface integration. Engineered for heavy-duty industrial applications, these security screws maintain clamping force under vibration and dynamic loads, making them ideal for manufacturing equipment, transportation systems, and permanent installations.

Specification Summary & Compliance

This fastener maintains precise Class 2A thread fit tolerance with 1/4"-20 UNC coarse threading and standard 82° flat head profile. Manufacturing complies with ASME B18.3 specifications for dimensional accuracy and performance standards. The product meets RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) regulations for environmental safety, ensuring suitability for global industrial markets and restricted substance requirements.