S-95635A547 1/4"-20 x 1 1/4" ASME B18.3 Tamper-Resistant Hex-Drive Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with specialized hex drive requiring unique tools, preventing unauthorized access in sensitive installations.
• Superior corrosion resistance from 18-8 stainless steel construction and passivated finish, ensuring long-term reliability in harsh environments.
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B70 hardness for high-stress applications without failure.
• Precise thread engagement through Class 3A thread fit and UNC coarse threading, enabling faster installation and reduced cross-threading risks.
• Full-threaded design maximizes grip length and load distribution across the entire 1-1/4" shaft for secure fastening.
• Low-profile rounded button head provides a smooth finish that minimizes snagging while maintaining aesthetic appeal.
• Compliance with major industrial standards including ASME B18.3, ensuring dimensional accuracy and interoperability.

Professional Applications & Engineering Value

This tamper-resistant hex screw addresses critical security and durability challenges in industrial settings. The 18-8 stainless steel material, combined with a passivated finish, offers robust protection against oxidation and chemical exposure, making it ideal for outdoor equipment, marine hardware, and food processing machinery. The UNC coarse thread and Class 3A thread fit ensure quick, reliable assembly with minimal effort, reducing labor time in high-volume production. Its fully threaded 1-1/4" length distributes clamping force evenly, preventing loosening under vibration—common in automotive, aerospace, and electronic enclosures. The tamper-resistant drive style deters vandalism and unauthorized disassembly in public infrastructure, securing access panels, utility boxes, and transportation systems effectively.

Specification Summary & Compliance

This screw features precise Class 3A thread fit and UNC coarse thread specifications (1/4"-20 size) per ASME B18.3 manufacturing standards. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are met. The dimensional accuracy includes a head diameter of 0.437", drive size of 5/32", and full threading along the 1-1/4" length for consistent performance in industrial fastening applications.