S-91781A078 2-56 x 5/16" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel and passivated finish, ideal for harsh environments and long-term reliability.
• Exceptional holding power from fully threaded 2-56 UNC coarse spacing, ensuring secure fastening in demanding applications.
• High tensile strength of 80,000 psi and Rockwell B80 hardness for reliable performance under heavy loads and stress.
• Precise 82° countersink angle allows for a flush, professional finish, minimizing protrusion and improving safety.
• Class 2A thread fit guarantees consistent, easy assembly and interchangeability, reducing installation time and errors.
• Compliance with ASME B18.6.3 ensures dimensional accuracy and meets rigorous industrial standards for quality assurance.
• RoHS 3 and REACH compliant for environmentally safe use, supporting sustainable and regulated manufacturing processes.

Professional Applications & Engineering Value

These 2-56 UNC flat head slotted screws are engineered to address common industrial challenges, such as corrosion and mechanical failure. Made from 18-8 stainless steel with a passivated finish, they offer excellent resistance to rust and chemicals, making them ideal for applications in electronics, machinery, and outdoor equipment where moisture exposure is a concern. The fully threaded coarse spacing and Class 2A fit provide quick, reliable installation with minimal risk of cross-threading, enhancing assembly efficiency. The flat head design with an 82° countersink ensures a smooth, low-profile fit, reducing snagging and improving aesthetic integration in precision assemblies. This combination of high tensile strength and standardized dimensions supports durable, long-lasting connections in industrial screws and corrosion-resistant fasteners, delivering consistent performance in critical engineering environments.

Specification Summary & Compliance

This screw features a 2-56 UNC thread size with Class 2A thread fit for precise dimensional accuracy and easy assembly. It complies with ASME B18.6.3 standards for uniformity and reliability, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material compliance. The fully threaded design and 82° countersink angle adhere to specified industrial tolerances, supporting consistent performance in professional applications.