S-91255A126 5-40 x 3/16" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance under high-stress conditions
• Superior corrosion resistance from black-oxide coating extends service life in demanding environments
• Precise Class 3A thread fit guarantees secure fastening with minimal vibration loosening
• Full threading design provides maximum grip and holding power across the entire fastener length
• Rockwell C39 hardness maintains structural integrity and prevents deformation during installation
• 5/64" hex drive compatibility enables quick installation with standard industrial tools
• Coarse UNC threading allows for rapid assembly and disassembly in time-sensitive operations

Professional Applications & Engineering Value

These black-oxide alloy steel screws deliver critical performance advantages for industrial applications where corrosion resistance and high tensile strength are paramount. The 5-40 UNC coarse thread configuration combined with Class 3A precision threading ensures secure fastening in vibration-prone environments, while the rounded button head design provides a low-profile finish that reduces snagging hazards. The fully threaded construction maximizes surface contact for superior load distribution, making these hex drive screws ideal for machinery assembly, electronic enclosures, and automotive components where durability and reliable performance are non-negotiable requirements.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 and ASTM F835 specifications with Class 3A thread fit tolerances for precision engineering applications. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards. Features 5-40 UNC coarse threading, right-hand thread direction, and fully threaded design with dimensional accuracy maintained throughout production.