S-91253A671 7/16"-14 x 1 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 130,000 psi tensile strength, these screws withstand high-stress applications without failure, ensuring long-term structural integrity.
• Superior Corrosion Resistance – The black-oxide finish on alloy steel provides enhanced protection against rust and environmental degradation in demanding industrial settings.
• Precise Thread Engagement – Class 3A thread fit ensures tight, reliable fastening with minimal risk of loosening, ideal for vibration-prone machinery.
• Optimized Drive Efficiency – Hex drive design allows for high-torque installation with standard tools, reducing assembly time and improving workplace productivity.
• Full Thread Coverage – Fully threaded design maximizes grip length and load distribution across the entire fastener, enhancing joint stability.
• Consistent Countersinking – 82° countersink angle enables flush mounting in prepared holes, creating smooth surfaces and reducing snag hazards.
• High Hardness Durability – Rockwell C39 hardness ensures the screw maintains its form and thread integrity under repeated use and mechanical stress.

Professional Applications & Engineering Value

These 7/16"-14 UNC flat head screws are engineered to address critical challenges in heavy-duty industrial environments. The black-oxide alloy steel construction combines high tensile strength with excellent corrosion resistance, making them suitable for outdoor equipment, machinery frames, and structural assemblies where exposure to moisture and chemicals is common. The coarse thread spacing and Class 3A thread fit provide rapid installation and secure fastening in materials like cast iron or thick steel plates, reducing the risk of cross-threading. The hex drive and fully threaded design allow for quick, tool-friendly assembly and uniform stress distribution, minimizing the need for frequent maintenance or replacements in high-vibration applications such as automotive, construction, and manufacturing systems.

Specification Summary & Compliance

This flat head screw adheres to precise dimensional standards, including Class 3A thread fit for superior tolerance control and UNC coarse thread specifications. Manufacturing and performance comply with ASME B18.3 and ASTM F835 standards, ensuring consistent quality and reliability. The product is also verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental and safety regulations for hazardous substance restrictions.