S-91900A305 M4 x 40 mm ASTM F879M, ISO 7380 Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with T15 Torx drive prevents unauthorized access in high-security applications
• Superior corrosion protection through 18-8 stainless steel construction and passivated finish for extended service life
• High mechanical strength with 80,000 psi tensile strength and Rockwell B96 hardness withstands demanding industrial loads
• Precision thread engagement with Class 6g metric coarse threads ensures reliable fastening in various materials
• Optimized head design featuring rounded button profile provides flush mounting and improved aesthetics
• Full threading capability along the entire 40mm length offers maximum grip and adjustment flexibility
• Regulatory compliance assurance meeting ASTM F879M, ISO 7380, RoHS 3, and REACH standards for global acceptance

Professional Applications & Engineering Value

These M4 metric screws with tamper-resistant Torx drive address critical security and durability challenges in industrial environments. The combination of 18-8 stainless steel material and passivated finish creates a robust barrier against corrosive elements, making them ideal for outdoor equipment, marine applications, and chemical processing facilities. The fully threaded design and Class 6g thread fit ensure consistent clamping force across the entire 40mm length, preventing loosening under vibration while the rounded button head minimizes snagging hazards in machinery and electronic enclosures. These security screws are particularly valuable for public infrastructure, transportation systems, and access panels where unauthorized tampering must be prevented without compromising structural integrity.

Specification Summary & Compliance

This metric screw features precise M4 x 0.7 mm coarse threading with Class 6g tolerance according to ISO standards, ensuring compatibility with standard metric fastening systems. Manufacturing complies with ASTM F879M and ISO 7380 specifications for dimensional accuracy and performance. The product is fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations concerning chemical safety, making them suitable for global industrial distribution and use in regulated industries.