S-91715A103 4-40 x 3/8" ASME B18.6.3, SAE J933 Tapping Screws

Key Features & Benefits at a Glance

• Self-tapping design eliminates the need for pre-tapped holes, reducing installation time and labor costs in aluminum, brass, cast iron, and sheet metal applications
• Black zinc-plated steel construction provides enhanced corrosion resistance for extended service life in demanding industrial environments
• Coarse UNC threading ensures rapid installation and superior holding power in softer materials and sheet metal assemblies
• Phillips drive (No. 1) offers secure tool engagement and controlled torque application during installation
• Fully threaded shank maximizes thread engagement along the entire fastener length for consistent clamping force distribution
• Standard pan head design combines low-profile appearance with effective bearing surface for reliable fastening performance
• Industry compliance meets ASME B18.6.3 and RoHS 3 standards, ensuring quality assurance and environmental responsibility

Professional Applications & Engineering Value

These 4-40 UNC thread cutting screws deliver exceptional engineering value by solving common fastening challenges in aluminum, brass, cast iron, and sheet metal applications. The thread cutting design (Type F) creates precise mating threads during installation, eliminating costly tapping operations while maintaining tight tolerances per UNC standards. The black zinc-plated steel surface treatment provides a durable barrier against corrosion, extending service life in industrial environments where moisture or chemical exposure may occur. With coarse thread spacing and right-hand threading, these tapping screws offer rapid installation and reliable performance in assembly lines, electrical enclosures, machinery components, and fabricated metal products where vibration resistance and long-term fastener integrity are critical.

Specification Summary & Compliance

These screws feature 4-40 UNC coarse threads with standard Class 2A tolerances, 3/8" length, and fully threaded configuration. Manufacturing complies with ASME B18.6.3 specifications (referencing SAE J933) for dimensional accuracy and performance standards. The products are RoHS 3 (2015/863/EU) compliant, ensuring environmental responsibility while maintaining the required mechanical properties for industrial fastening applications. Proper installation requires a No. 41 drill bit (0.096" diameter) for optimal thread engagement and holding strength.