S-91870A130 4-40 x 3/8" ASME B18.3 Tamper-Resistant Torx Stainless Steel Flat Head Screws
Tamper-Resistant Torx Stainless Steel Flat Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Enhanced tamper resistance with T8 Torx drive prevents unauthorized access in security-critical applications
- Superior corrosion protection through 18-8 stainless steel construction and passivated finish for extended service life
- High-strength performance with 70,000 psi tensile strength and Rockwell B70 hardness for reliable fastening under stress
- Precision thread engagement with Class 2A UNC coarse threads ensuring consistent installation and vibration resistance
- Optimized flush mounting featuring standard 82° countersink angle for seamless surface integration
- Full-thread design provides maximum grip length and load distribution across the entire fastener
- Regulatory compliance meeting ASME B18.3, RoHS 3, and REACH standards for quality assurance and environmental safety
Professional Applications & Engineering Value
These 4-40 UNC flat head tamper-resistant Torx screws deliver critical security and reliability for industrial applications where unauthorized tampering poses operational risks. The 18-8 stainless steel material combined with passivated finish creates a robust barrier against corrosive environments, making these fasteners ideal for electronic enclosures, medical devices, and public infrastructure. The T8 tamper-resistant Torx drive provides secure installation while preventing casual disassembly, addressing security vulnerabilities in access panels and control systems. With fully threaded coarse UNC patterning and Class 2A thread fit, these screws maintain consistent clamping force in vibration-prone assemblies, while the 82° countersink angle ensures flush mounting without protrusion interference.
Specification Summary & Compliance
This 4-40 UNC flat head screw features precision Class 2A thread fit with coarse thread spacing and full threading along the 3/8" length. Manufactured to ASME B18.3 specifications, the fastener delivers consistent dimensional accuracy and mechanical performance. The product complies with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations for chemical safety, ensuring environmental responsibility and regulatory acceptance in global markets.
