S-96669A202 4-40 x 3/8" ASME B18.3 Sealing Tamper-Resistant Torx Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced Security: Tamper-resistant Torx T8 drive prevents unauthorized removal, ideal for public or high-security installations.
• Reliable Sealing: Integrated Buna-N rubber O-ring provides a tight seal against moisture and contaminants, withstanding pressures up to 1500 psi.
• Superior Corrosion Resistance: 18-8 Stainless Steel with passivated finish ensures long-lasting performance in harsh environments.
• Broad Temperature Tolerance: O-ring maintains integrity from -40 to 225°F, suitable for varied industrial applications.
• Optimized Fastening: Undercut flat head design allows for flush mounting, reducing protrusion and improving aesthetics.
• High Tensile Strength: With 70,000 psi tensile strength, it delivers robust holding power for demanding assemblies.
• Precision Threading: Fully threaded 4-40 UNC coarse thread with Class 2A fit ensures easy installation and consistent engagement.

Professional Applications & Engineering Value

This 4-40 UNC flat head screw is engineered to address critical challenges in industrial and security-focused applications. Its tamper-resistant Torx T8 drive deters vandalism and unauthorized access, making it perfect for public infrastructure, electronic enclosures, and machinery requiring controlled maintenance. The combination of 18-8 stainless steel and a passivated finish provides exceptional resistance to corrosion, extending service life in humid or chemical-exposed settings. The integrated Buna-N rubber O-ring ensures reliable sealing against fluids and dust, supporting operations in automotive, HVAC, and outdoor equipment where pressure fluctuations up to 1500 psi occur. The undercut flat head profile facilitates a smooth, countersunk fit, minimizing snagging and enhancing safety in assembled products.

Specification Summary & Compliance

This screw features a 4-40 UNC coarse thread with Class 2A fit for precise dimensional accuracy, ensuring reliable fastening in standard hole diameters up to 0.127". It is manufactured in compliance with ASME B18.3 specifications for consistency and interoperability. Additionally, the product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, confirming its environmental and safety adherence for global industrial use.