S-90128A596 5/16"-18 x 3 1/4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance with zinc-plated alloy steel construction, extending service life in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• Robust Rockwell C37 hardness offers excellent wear resistance, maintaining thread integrity through repeated use and adjustments.
• Convenient 1/4" hex drive allows for easy installation and removal with standard tools, speeding up assembly processes.
• Compliance with ASTM A574 guarantees consistent quality and performance, meeting rigorous industrial standards for socket head cap screws.
• Environmental regulatory adherence including RoHS 3 and REACH ensures safe, sustainable use across global markets.

Professional Applications & Engineering Value

This 5/16"-18 UNC socket head cap screw is engineered to address critical challenges in heavy-duty machinery, automotive, and construction sectors. The zinc-plated alloy steel material provides a durable barrier against corrosion, essential for outdoor or humid conditions, while the coarse thread design enables quick assembly and superior grip in softer materials. With a partially threaded shank, it offers optimal clamping force without compromising structural integrity, making it ideal for precision equipment where vibration resistance and high-strength fastening are paramount. The standard socket head profile and right-hand thread ensure compatibility with common tools, streamlining maintenance and reducing downtime in industrial operations.

Specification Summary & Compliance

This fastener adheres to Class 3A thread fit for precise dimensional accuracy under UNC standards, with a thread size of 5/16"-18 and a minimum thread length of 1 1/8". It conforms to ASTM A574 manufacturing specifications, ensuring consistent mechanical properties, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations for environmental safety.