S-96640A262 4-40 x 5/16" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide coated 18-8 Stainless Steel, ideal for harsh industrial environments.
• High tensile strength of 80,000 psi ensures reliable fastening under heavy loads and vibrations.
• Precise Class 2A thread fit provides smooth assembly and consistent engagement in coarse UNC threading.
• Undercut flat head design allows for flush mounting, reducing snagging and improving aesthetics.
• 82° countersink angle ensures secure seating in standard countersunk holes for stable connections.
• Fully threaded shank offers maximum grip length and uniform load distribution along the entire fastener.
• Compliance with ASME B18.6.3, RoHS 3, and REACH guarantees quality, safety, and environmental standards for global applications.

Professional Applications & Engineering Value

These 4-40 UNC flat head Phillips screws are engineered to address common industrial challenges, such as corrosion in humid or chemical-exposed settings. The Black-Oxide 18-8 Stainless Steel material provides excellent durability and oxidation resistance, extending service life in machinery, electronics, and outdoor equipment. The undercut flat head profile and 82° countersink angle enable seamless, low-profile installations, minimizing protrusion risks in tight spaces. With a coarse thread and Class 2A fit, these screws ensure quick, reliable fastening in metal, plastic, or composite assemblies, reducing installation time and maintenance needs. Ideal for industrial applications requiring high-strength, corrosion-resistant fasteners, they deliver consistent performance in automotive, aerospace, and consumer goods sectors.

Specification Summary & Compliance

These screws feature precise Class 2A thread fit per UNC standards, with a coarse thread spacing and right-hand thread direction for standardized compatibility. Manufacturing adheres to ASME B18.6.3 specifications, ensuring dimensional accuracy for the 5/16" length, flat head diameter of 0.212", and Phillips No. 1 drive. Compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming they are free from hazardous substances and suitable for regulated industries.