S-91870A470 M4 x 25 mm ASTM F879M Tamper-Resistant Torx Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with a T20 Torx drive, providing superior security against unauthorized access in sensitive industrial environments.
• Exceptional corrosion resistance due to the 18-8 stainless steel material and passivated finish, ensuring long-term durability in harsh conditions.
• Reliable high-strength performance with 80,000 psi tensile strength and Rockwell B96 hardness, offering robust holding power for demanding applications.
• Precise thread engagement with Class 6g fit and coarse M4 x 0.7mm threading, enabling easy installation and secure fastening in various materials.
• Full threading design for maximum grip along the entire 25mm length, distributing load evenly and reducing the risk of loosening.
• Compliance with international standards including ASTM F879M, RoHS 3, and REACH, ensuring safety, environmental responsibility, and consistent quality.
• Standard flat head profile with 90° countersink for a flush, low-profile finish that minimizes protrusion and improves aesthetics in assembled products.

Professional Applications & Engineering Value

This M4 flat head screw is engineered to address critical challenges in industrial and security-focused applications. The 18-8 stainless steel construction, combined with a passivated finish, provides excellent resistance to corrosion and wear, making it ideal for use in electronics, machinery, and outdoor equipment where environmental factors are a concern. The tamper-resistant Torx drive (T20) deters vandalism and unauthorized disassembly, ensuring the integrity of public infrastructure, medical devices, and transportation systems. With a fully threaded metric coarse design and Class 6g thread fit, it offers quick installation and reliable performance in metal, plastic, and composite materials, reducing maintenance needs and enhancing product lifespan.

Specification Summary & Compliance

This screw features precise metric coarse threading (M4 x 0.7mm) with a Class 6g thread fit for consistent engagement and tolerance. It adheres to ASTM F879M specifications for mechanical properties and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for global industrial use.