S-90128A603 5/16"-18 x 4 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Superior corrosion resistance from zinc plating protects against rust and extends service life in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies with minimal backlash.
• Hex socket drive design allows for high-torque installation in confined spaces, improving assembly efficiency.
• Coarse UNC threads enable faster installation and better resistance to loosening in dynamic applications.
• Partially threaded shank offers optimal grip and clamping force control for precise joint integrity.
• Rockwell C37 hardness maintains dimensional stability and wear resistance over repeated use.

Professional Applications & Engineering Value

These zinc-plated alloy steel socket head cap screws deliver critical performance in demanding applications where reliability is non-negotiable. The 5/16"-18 UNC coarse thread configuration combined with a Class 3A fit ensures rapid assembly and superior vibration resistance in machinery, automotive subsystems, and heavy equipment. The hex drive socket facilitates high torque application without stripping, while the partial threading allows for precise clamp load distribution. Engineered to ASTM A574 specifications, these screws prevent joint failure in high-vibration environments, reducing maintenance downtime and enhancing operational safety across industrial and manufacturing sectors.

Specification Summary & Compliance

This socket head cap screw features a 5/16"-18 UNC coarse thread with Class 3A fit for precision threading applications. It meets ASTM A574 manufacturing standards for high-strength alloy steel fasteners and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in regulated industries.