S-97763A321 4-40 x 5/8" ASME B18.3 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from Black-Oxide 18-8 Stainless Steel, ideal for harsh industrial environments.
• High tensile strength of 70,000 psi ensures reliable, long-lasting fastening under stress.
• Precise Class 3A thread fit provides secure engagement and reduces the risk of stripping.
• Hex drive (1/16") design allows for easy installation and high torque application.
• Fully threaded right-hand coarse (UNC) design offers quick assembly and strong holding power.
• Rounded button head profile delivers a smooth finish and reduces surface damage.
• Compliance with ASME B18.3, RoHS, and REACH guarantees quality and environmental safety.

Professional Applications & Engineering Value

This 4-40 UNC thread screw in Black-Oxide 18-8 Stainless Steel is engineered to address common industrial challenges such as corrosion and mechanical failure. The rounded head with hex drive ensures easy installation in tight spaces, while the fully threaded coarse spacing provides rapid, secure fastening in materials like metal and plastic. With a Rockwell B55 hardness and 70,000 psi tensile strength, it withstands high-stress applications in machinery, electronics, and automotive assemblies, reducing maintenance needs and enhancing operational reliability.

Specification Summary & Compliance

This screw features a 4-40 UNC thread with Class 3A fit, ensuring precise dimensional accuracy. It is manufactured to meet ASME B18.3 standards and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for global industrial use without hazardous substances.