S-91255A018 2-56 x 3/4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with black-oxide coating on alloy steel, extending service life in demanding environments
• Superior mechanical strength with 120,000 psi tensile strength and Rockwell C39 hardness for reliable performance under high stress
• Precise thread engagement with Class 3A fit and UNC coarse spacing, ensuring secure fastening and vibration resistance
• Efficient installation via 0.050" hex drive, providing excellent torque transfer and reducing tool slippage
• Full thread coverage along the 3/4" length, maximizing grip and load distribution in assemblies
• Industry-standard compliance with ASME B18.3 and ASTM F835, guaranteeing interchangeability and quality consistency
• Environmental responsibility through RoHS 3 and REACH compliance, meeting global regulatory requirements

Professional Applications & Engineering Value

Engineered for precision-critical assemblies, this black-oxide alloy steel rounded head screw combines high tensile strength with excellent corrosion protection to address common industrial challenges like fastener failure in high-vibration environments. The UNC coarse thread spacing and Class 3A thread fit ensure rapid installation and reliable clamping force in metals and engineered plastics, while the fully threaded design distributes stress evenly across the entire 3/4" length. Ideal for machinery, electronics, and automotive applications, the hex drive facilitates secure tool engagement, reducing assembly time and improving maintenance accessibility in confined spaces.

Specification Summary & Compliance

This fastener maintains Class 3A thread fit per UNC standards with coarse spacing, manufactured to ASME B18.3 and ASTM F835 specifications for dimensional accuracy. It fully complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to restricted substance directives for global industrial use.