S-91870A751 1/4"-20 x 5/8" ASME B18.3 Tamper-Resistant Torx Plus Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with the specialized Torx Plus IPR30 drive, deterring unauthorized access and tool slippage in high-security environments.
• Superior corrosion resistance provided by 18-8 Stainless Steel and a passivated finish, ensuring long-term reliability in harsh or outdoor conditions.
• High-strength performance with a tensile strength of 70,000 psi and Rockwell B70 hardness, offering dependable load-bearing capacity for demanding applications.
• Precise, secure fastening through Class 3A coarse UNC threading, enabling quick installation and a tight, vibration-resistant fit.
• Flush, professional finish with a standard 82° countersink angle and flat head design, minimizing protrusion and improving aesthetic integration.
• Full regulatory compliance with ASME B18.3, RoHS 3, and REACH, ensuring safety, environmental responsibility, and industry-standard quality.
• Versatile right-hand threading and fully threaded shank for consistent grip and ease of use across various assembly tasks.

Professional Applications & Engineering Value

This 1/4"-20 x 5/8" flat head screw is engineered to address critical needs in industrial and security-focused settings. The combination of 18-8 Stainless Steel and a passivated finish provides exceptional resistance to rust and chemical exposure, making it ideal for machinery, outdoor equipment, and marine applications. The tamper-resistant Torx Plus drive (IPR30) prevents vandalism and unauthorized disassembly, crucial for public infrastructure, electrical enclosures, and transportation systems. Its Class 3A coarse UNC threading ensures rapid, secure installation even in materials prone to stripping, while the 82° countersink angle allows for a smooth, flush surface—reducing snag risks and improving safety. These features collectively deliver reliability, durability, and compliance, supporting efficient maintenance and long-term operational integrity.

Specification Summary & Compliance

This screw adheres to precise dimensional and performance standards, including Class 3A thread fit for superior tolerance and UNC coarse threading (1/4"-20) with a right-hand direction. Manufacturing and quality are governed by ASME B18.3 specifications. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental suitability for global industrial use.