S-91255A071 2-56 x 5/8" 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 mechanical strength from alloy steel construction, delivering 120,000 psi tensile strength for heavy-duty applications
• Precise Class 3A thread fit ensures secure, vibration-resistant fastening in critical assemblies
• Hex drive compatibility with 0.050" drive size enables efficient installation with standard tools
• Fully threaded design provides maximum grip and load distribution across the entire length
• Rounded button head profile offers a low-profile, aesthetically clean finish while reducing snagging risks
• Regulatory compliance assurance with RoHS 3 and REACH standards for global market acceptance

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these 2-56 UNC rounded head screws combine black-oxide alloy steel construction with Class 3A thread precision to solve critical fastening challenges. The fully threaded coarse pitch design prevents loosening under vibration while the hex drive configuration ensures torque reliability during assembly. Ideal for precision equipment, automotive subsystems, and electronic enclosures requiring corrosion-resistant fasteners with 120,000 psi tensile strength, these screws maintain integrity in high-stress applications where fastener failure is not an option.

Specification Summary & Compliance

Manufactured to ASME B18.3 and ASTM F835 specifications with Class 3A thread fit tolerance for precision assembly. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Features UNC coarse threading with 2-56 thread size and 5/8" length, hardened to Rockwell C39 for consistent performance.