S-91263A727 5/16"-18 x 5/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc plating that protects against rust and extends service life in demanding environments
• Superior tensile strength of 130,000 psi ensures reliable performance under high-stress conditions and prevents fastener failure
• Precise Class 3A thread fit provides tighter tolerances for secure mating with nuts and threaded components, reducing vibration loosening
• Fully threaded design maximizes grip and load distribution across the entire length for enhanced holding power
• 82° countersink angle with standard flat head profile allows for flush mounting in tapered seats, improving aesthetics and reducing snag hazards
• Rockwell C39 hardness rating offers excellent wear resistance and maintains thread integrity during repeated installations
• 3/16" hex drive compatibility enables easy installation with standard tools, speeding up assembly processes

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws are engineered from zinc-plated alloy steel to address critical industrial fastening challenges, such as vibration-induced loosening and environmental corrosion. The coarse thread design ensures quick assembly and reliable performance in materials like cast iron or soft metals, while the fully threaded configuration provides consistent clamping force across joints. Ideal for machinery, automotive, and structural applications, these screws deliver high-strength and durability, meeting rigorous standards for heavy-duty fasteners. Their compliance with ASTM F835 guarantees consistent quality, making them a trusted choice for engineers seeking corrosion-resistant and long-lasting fastening solutions.

Specification Summary & Compliance

These screws feature a 5/16"-18 UNC coarse thread with Class 3A thread fit for precise dimensional accuracy, ensuring optimal engagement. Manufactured in accordance with ASTM F835 specifications, they meet stringent mechanical and performance criteria. Additionally, they are RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety regulations for hazardous substances.