S-91255A831 3-48 x 3/4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating for extended service life in demanding environments
• Exceptional mechanical strength with 120,000 psi tensile strength and Rockwell C39 hardness for heavy-duty applications
• Precise Class 3A thread fit ensures secure fastening with minimal vibration loosening in critical assemblies
• Easy installation and removal with 1/16" hex drive design providing reliable tool engagement
• Optimized thread engagement through UNC coarse threading and full threading along the 3/4" length
• Space-saving rounded button head profile allows for flush mounting where clearance is limited
• Right-hand thread direction provides standard, intuitive fastening operation for maintenance crews

Professional Applications & Engineering Value

These black-oxide alloy steel rounded head screws deliver critical performance in industrial settings where vibration resistance and corrosion protection are paramount. The Class 3A UNC thread fit maintains tight tolerances in machinery, automotive, and electronic enclosures, preventing joint failure under dynamic loads. With 120,000 psi tensile strength and Rockwell C39 hardness, they withstand extreme mechanical stress while the coarse thread spacing ensures rapid installation in production lines. The fully threaded design provides consistent clamping force across the entire 3/4" length, making them ideal for securing components of varying thicknesses in assembly applications.

Specification Summary & Compliance

Manufactured to ASME B18.3 and ASTM F835 specifications with Class 3A thread fit precision. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Features UNC coarse threads with right-hand direction in inch system measurements, ensuring compatibility with standard industrial components and tooling.