S-91870A230 1/4"-20 x 3/8" ASME B18.3 Tamper-Resistant Torx Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with specialized T27 Torx drive that prevents unauthorized removal in security-sensitive applications
• Superior corrosion protection through 18-8 stainless steel construction and passivated surface treatment for extended service life
• Optimized flush mounting with undercut flat head design that sits perfectly flush while reducing material stress
• Reliable thread engagement with UNC coarse threading and Class 2A fit ensuring consistent performance in various materials
• High mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Quick installation with 82° countersink angle that facilitates precise alignment and efficient assembly
• Full regulatory compliance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

This tamper-resistant flat head screw addresses critical security and durability challenges across multiple industries. The combination of 18-8 stainless steel material and passivated finish provides exceptional resistance to corrosion and chemical exposure, making it ideal for outdoor equipment, marine applications, and harsh industrial environments. The undercut flat head profile minimizes stress concentration while ensuring flush mounting in precision assemblies. With its T27 tamper-resistant Torx drive, this security fastener prevents unauthorized access in public infrastructure, electrical enclosures, and transportation systems. The UNC coarse thread configuration offers superior holding power in various substrates, while the fully threaded design ensures maximum engagement length for enhanced pull-out resistance in critical connections.

Specification Summary & Compliance

This security screw maintains precise Class 2A thread fit tolerances with 1/4"-20 UNC coarse threading and features a standardized 82° countersink angle for proper seating. Manufacturing follows ASME B18.3 specifications for dimensional accuracy and performance reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets while meeting industrial quality standards for security fasteners.