S-91781A074 2-56 x 1/8" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh environments and long-term reliability.
• Exceptional mechanical strength offering 80,000 psi tensile strength and Rockwell B80 hardness to withstand high-stress applications without failure.
• Precision thread engagement with UNC coarse threads and Class 2A fit for quick, secure installation and reduced cross-threading risks.
• Flush, low-profile seating thanks to the flat head with 82° countersink angle and undercut profile, minimizing protrusion and improving aesthetics.
• Broad regulatory compliance meeting ASME B18.6.3, RoHS 3, and REACH standards, ensuring safety and environmental responsibility.
• Versatile fastening solution with fully threaded design and right-hand thread direction, suitable for various industrial assembly needs.
• Easy manual installation using standard slotted drive, providing straightforward tool compatibility and control during tightening.

Professional Applications & Engineering Value

This 2-56 UNC flat head screw is engineered to address common industrial challenges like corrosion, vibration loosening, and space constraints. The 18-8 stainless steel material, combined with a passivated finish, provides excellent resistance to rust and chemicals, making it ideal for electronics, machinery, and outdoor equipment. The flat head with undercut profile and 82° countersink angle ensures a secure, flush fit in tapered holes, reducing stress concentration and improving load distribution. With coarse UNC threads and Class 2A fit, it offers reliable grip in softer materials and faster assembly, while the fully threaded design enhances holding power across the entire length. These features make it a dependable choice for applications requiring durability, precision, and compliance with industry standards.

Specification Summary & Compliance

This screw adheres to precise dimensional tolerances, including Class 2A thread fit and UNC coarse threading with a thread size of 2-56. It meets ASME B18.6.3 specifications for consistency and performance, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and safe for various industrial uses.