S-90429A131 5/16"-24 x 3 1/2" 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 under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life and maintaining integrity in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• Hex drive design allows for easy installation and high torque application, speeding up assembly processes without stripping.
• 82° countersink angle and flat head profile enable a flush fit, enhancing aesthetics and preventing snagging in machinery or equipment.
• Fine thread spacing (UNF) offers improved holding power and better adjustment in materials prone to vibration or thermal expansion.
• Partial threading allows for focused grip on specific sections, ideal for applications requiring controlled clamping force.

Professional Applications & Engineering Value

These 5/16"-24 UNF flat head screws are engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in machinery. Made from black-oxide alloy steel, they combine high Rockwell C39 hardness and 130,000 PSI tensile strength to withstand heavy loads and repetitive stress in automotive, aerospace, and manufacturing setups. The fine thread spacing and Class 3A fit ensure precise alignment and durability, while the hex drive and 82° countersink facilitate quick, flush installations—reducing maintenance downtime and enhancing operational efficiency in industrial fastening applications.

Specification Summary & Compliance

This product adheres to Class 3A thread fit for high precision and meets ASME B18.3 and ASTM F835 standards, ensuring consistent quality and performance. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in global markets.