S-91900A537 1/4"-20 x 1/2" ASME B18.3 Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Superior tamper resistance with specialized Torx T27 drive that deters unauthorized removal in high-security environments
• Exceptional corrosion protection through 18-8 stainless steel construction and passivated surface treatment for long-term reliability
• Maximum thread engagement with Class 3A fit and UNC coarse threading ensuring vibration-resistant, secure fastening
• High-strength performance delivering 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Optimized head design featuring low-profile rounded button head that provides flush mounting without compromising security
• Full threading coverage along the entire 1/2" length for consistent clamping force and installation flexibility
• Regulatory compliance meeting ASME B18.3 standards and environmental regulations for global industrial use

Professional Applications & Engineering Value

These tamper-resistant Torx screws address critical security challenges in industrial settings where unauthorized access poses significant risks. The combination of 18-8 stainless steel material and passivated finish creates a robust barrier against corrosion, making them ideal for outdoor equipment, marine applications, and harsh manufacturing environments. The T27 security drive system prevents casual tampering while allowing authorized maintenance with proper tools. With Class 3A thread fit and UNC coarse threading, these fasteners maintain secure connections in high-vibration machinery, public infrastructure, and electronic enclosures where reliability is paramount. The fully threaded design ensures maximum grip length in various material thicknesses, while the rounded button head provides a clean, low-profile appearance that discourages prying attempts.

Specification Summary & Compliance

This security screw maintains precision Class 3A thread fit with UNC 1/4"-20 coarse threading and right-hand direction. Manufacturing complies with ASME B18.3 specifications for dimensional accuracy and performance standards. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring safe use in restricted applications. The fastener delivers verified mechanical properties including 70,000 psi tensile strength and Rockwell B70 hardness for consistent performance in security-critical installations.