S-90086A604 2-56 x 5/16" ASME B18.6.3, SAE J933 Tapping Screws

Key Features & Benefits at a Glance

• Superior material protection with zinc-plated steel construction offering excellent corrosion resistance for extended service life in demanding environments.
• Efficient self-tapping installation with Type F thread cutting design eliminates the need for pre-tapped holes, reducing assembly time and labor costs.
• Optimized for diverse materials including aluminum, brass, cast iron, and sheet metal, providing versatile application across various industrial projects.
• Enhanced drive stability with Phillips No. 1 drive style and flat head design ensures secure fastening and flush surface finish with standard 82° countersink angles.
• Reliable holding power through coarse UNC threading and full threading along the 5/16" length delivers maximum grip and vibration resistance.
• Guaranteed dimensional precision manufactured to ASME B18.6.3 standards ensuring consistent fit, performance, and interchangeability.
• Environmentally compliant operation meeting RoHS 3 directives for safe use in regulated industries and global markets.

Professional Applications & Engineering Value

These 2-56 UNC zinc-plated steel tapping screws are engineered to address critical challenges in metal assembly, where traditional fasteners often fail. The thread cutting design (Type F) with coarse spacing and blunt tip enables precise, clean thread formation in aluminum, brass, cast iron, and sheet metal without causing material cracking or strip-out. The zinc-plated finish provides a protective barrier against oxidation, extending fastener life in humid or corrosive industrial settings. Combined with the Phillips flat head and standardized 82° countersink, these screws ensure flush mounting for aerodynamic surfaces and equipment panels, reducing protrusion risks. Ideal for high-volume production lines, they streamline installation with No. 49 drill bit compatibility, minimizing tool changes and enhancing workflow efficiency in automotive, machinery, and electronic enclosures.

Specification Summary & Compliance

This product adheres to UNC coarse thread standards with a 2-56 thread size, 0.086" thread diameter, and full threading for uniform load distribution. Manufactured to ASME B18.6.3 specifications (referencing SAE J933), it guarantees precise dimensional tolerances, including a head diameter of 0.162" and length of 5/16". Compliance with RoHS 3 (2015/863/EU) ensures the absence of hazardous substances, supporting sustainable procurement practices. The screws are designed for use with a No. 49 drill bit (0.073" diameter) and feature a standard 82° countersink angle for seamless integration into pre-drilled holes.