S-90128A582 5/16"-18 x 7/8" 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 industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from zinc-plated alloy steel construction extends service life in harsh or outdoor environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides secure, vibration-resistant connections, enhancing assembly integrity and reducing loosening over time.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated installations and removals.
• Standard hex drive (1/4") allows for easy installation with common tools, speeding up assembly processes and improving workflow efficiency.
• Fully threaded design ensures consistent clamping force along the entire length, providing uniform load distribution in critical joints.
• Compliance with ASTM A574 and RoHS 3 guarantees material quality and environmental safety, meeting rigorous industry standards for professional use.

Professional Applications & Engineering Value

This zinc-plated alloy steel socket head cap screw addresses common industrial challenges where corrosion resistance and high tensile strength are paramount. The UNC coarse thread design facilitates quick assembly in materials like steel and cast iron, while the Class 3A thread fit prevents backlash in precision machinery. Engineered to withstand extreme mechanical loads up to 170,000 psi, it is ideal for heavy-duty equipment, automotive assemblies, and construction frameworks. The zinc plating provides a protective barrier against moisture and chemicals, making these socket head cap screws suitable for outdoor or corrosive environments without compromising on Rockwell C37 hardness for durability.

Specification Summary & Compliance

This socket head cap screw features a 5/16"-18 UNC coarse thread with Class 3A tolerance for precise fit, and is fully threaded with a right-hand direction. It meets ASTM A574 specifications for high-strength alloy steel fasteners and is RoHS 3 (2015/863/EU) compliant, ensuring adherence to environmental regulations. Dimensions include a 7/8" length, 1/4" hex drive, and standard socket head profile for consistent performance in industrial applications.