S-91900A834 4-40 x 3/8" Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with specialized T8 Torx drive that deters unauthorized access while providing secure installation
• Superior corrosion resistance through 18-8 stainless steel construction with passivated surface treatment for extended service life
• Precise thread engagement with Class 3A thread fit ensuring reliable fastening in critical applications
• Exceptional mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for heavy-duty performance
• Maximum holding power through fully threaded design that distributes load evenly across the entire fastener length
• Regulatory compliance assurance meeting RoHS 3 and REACH environmental standards for global industrial use
• Optimized installation efficiency with coarse UNC threading and right-hand direction for rapid assembly in production environments

Professional Applications & Engineering Value

These 4-40 UNC tamper-resistant Torx screws provide critical security solutions where unauthorized access prevention is paramount. The 18-8 stainless steel construction with passivated finish delivers exceptional corrosion resistance in harsh environments, while the T8 drive system ensures only authorized personnel can perform maintenance or disassembly. The rounded button head profile offers a clean, low-profile appearance that reduces snagging in confined spaces. Engineered with Class 3A thread fit, these fasteners maintain precise tolerances for vibration-resistant connections in electronics enclosures, industrial machinery, public infrastructure, and security systems. The fully threaded design maximizes grip length, distributing stress evenly to prevent loosening under dynamic loads.

Specification Summary & Compliance

This security fastener features precision 4-40 UNC coarse threading with Class 3A thread fit for superior engagement in mating components. Manufacturing adheres to strict dimensional standards with 3/8" length and right-hand thread direction. The product fully complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and global market acceptance. Mechanical properties include 70,000 psi tensile strength and Rockwell B70 hardness for reliable performance in demanding industrial applications.