S-90729A612 4-40 x 1/4" Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel and passivated finish, ideal for harsh industrial environments
• Precise, reliable fastening ensured by Class 3A thread fit and UNC coarse threading for consistent engagement
• High mechanical strength with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Efficient installation and removal using the 1/16" hex drive, reducing assembly time and tool wear
• Secure flush mounting with a 100° countersink angle and undercut flat head profile for smooth surface finishes
• Full thread coverage along the 1/4" length provides maximum grip and load distribution
• Compliance with environmental regulations including RoHS 3 and REACH, ensuring safe and sustainable use

Professional Applications & Engineering Value

This 4-40 UNC flat head screw in 316 stainless steel is engineered to address common industrial challenges such as corrosion, vibration loosening, and high-stress conditions. The passivated finish enhances durability in moist or chemical-exposed settings, while the Class 3A thread fit and coarse thread spacing deliver superior holding power in materials like metal, plastic, or composites. Its hex drive and undercut head allow for efficient torque application and a clean, flush installation, minimizing protrusions in precision assemblies. Ideal for machinery, electronics, and marine equipment, this screw ensures long-term reliability and reduces maintenance needs in industrial applications.

Specification Summary & Compliance

This product adheres to UNC thread standards with a Class 3A fit for precise dimensional accuracy. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring environmental safety. Specifications include a 1/4" length, 100° countersink angle, and fully threaded design, manufactured to high tolerances for consistent performance in professional fastening systems.