S-91900A845 1/4"-20 x 5/8" Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Maximum tamper resistance with T27 Torx drive requiring specialized tools, preventing unauthorized access in secure installations
• Superior corrosion resistance through 18-8 stainless steel construction with passivated finish, ensuring longevity in harsh environments
• Precise thread engagement with Class 3A UNC coarse threading, providing reliable fastening with reduced cross-threading risk
• High mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for demanding industrial applications
• Enhanced security profile with rounded button head design that resists gripping with conventional tools
• Full thread coverage along the 5/8" length for maximum grip and load distribution across the entire fastener
• Environmental compliance meeting RoHS 3 and REACH standards for safe use in regulated industries

Professional Applications & Engineering Value

These tamper-resistant Torx rounded head screws address critical security and durability challenges in industrial settings. The 18-8 stainless steel composition with passivated finish provides exceptional resistance to corrosion, oxidation, and chemical exposure, making them ideal for outdoor equipment, marine applications, and chemical processing facilities. The T27 drive system offers superior torque transmission compared to standard security fasteners while preventing casual tampering. With Class 3A thread fit and UNC coarse threading, these screws ensure rapid installation and reliable performance in vibration-prone applications such as machinery guards, electrical enclosures, and public infrastructure. The combination of 70000 psi tensile strength and fully threaded design creates a secure fastening solution that maintains integrity under mechanical stress and thermal cycling.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread fit for superior engagement and UNC 1/4"-20 coarse threading for rapid installation. The rounded button head profile measures 0.437" diameter with 0.132" height, compatible with standard counterbores. These security fasteners comply with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring they contain no restricted substances. The manufacturing process maintains strict adherence to dimensional tolerances and material properties, delivering consistent performance across production batches for industrial and commercial applications requiring reliable, secure fastening solutions.