S-91263A217 1/2"-13 x 4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 PSI ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance with zinc-plated alloy steel construction, extending service life in harsh environments and minimizing maintenance needs.
• Precise Class 3A thread fit guarantees tight, secure connections with minimal play, enhancing assembly accuracy and vibration resistance.
• Partially threaded design allows for controlled clamping force, preventing over-tightening and material damage in sensitive assemblies.
• Heavy-duty Rockwell C39 hardness provides excellent wear resistance, maintaining thread integrity through repeated installations.
• Standard 82° countersink angle ensures flush mounting in prepared surfaces, creating smooth finishes and reducing snag hazards.
• 5/16" hex drive compatibility offers efficient installation with common tools, speeding up assembly processes in production environments.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these 1/2"-13 UNC flat head screws solve critical fastening challenges in machinery, structural frameworks, and heavy equipment assembly. The zinc-plated alloy steel construction provides essential corrosion protection in manufacturing environments where exposure to moisture and chemicals is common. The coarse thread spacing and Class 3A thread fit deliver superior vibration resistance, preventing loosening in dynamic applications. With partially threaded design, these screws enable precise clamping control for materials requiring specific compression points. The flat head profile with standard 82° angle ensures seamless integration into countersunk holes, maintaining surface integrity while providing high-strength fastening solutions for industrial maintenance and OEM applications.

Specification Summary & Compliance

This 4" flat head screw features precise Class 3A thread fit with 1/2"-13 UNC coarse threads and right-hand thread direction. Manufacturing complies with ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and performance reliability. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental and safety standards for industrial fastener applications.