S-91255A022 4-40 x 9/16" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating, ideal for harsh industrial environments
• Superior tensile strength of 120,000 psi ensures reliable performance under high-stress applications
• Precise Class 3A thread fit guarantees secure, vibration-resistant fastening in critical assemblies
• Hex drive design allows for easy installation and removal with standard tools, reducing assembly time
• Fully threaded construction provides maximum grip and load distribution along the entire length
• Rounded button head profile offers a low-profile, snag-free finish for safety and aesthetics
• Compliance with major industry standards including ASME B18.3 and ASTM F835 ensures consistent quality and reliability

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these 4-40 UNC thread screws with coarse threading and Class 3A fit deliver superior holding power in machinery, electronics, and automotive assemblies. The black-oxide alloy steel construction resists rust and wear, extending service life in corrosive or high-moisture environments. The rounded head and hex drive facilitate quick, tool-accessible installation in tight spaces, reducing labor costs and minimizing assembly errors. Ideal for high-tensile applications where vibration resistance and durability are critical, these screws meet rigorous engineering specifications for precision fastening solutions.

Specification Summary & Compliance

This screw features a 4-40 UNC coarse thread with Class 3A tolerance for precise fit, manufactured from alloy steel with a black-oxide surface finish. It complies with ASME B18.3 and ASTM F835 standards, ensuring dimensional accuracy and mechanical performance. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming adherence to hazardous substance restrictions and sustainable manufacturing practices.