S-91274A224 5/16"-18 x 3/8" ASME B18.3, ASTM A574, ASTM B117 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 provided by the zinc-flake coating, extending service life in harsh industrial environments.
• High hardness rating of Rockwell C37 offers excellent wear resistance and durability under repetitive loads.
• Precise Class 3A thread fit guarantees secure, vibration-resistant connections with minimal risk of loosening.
• Standard hex drive design allows for easy installation and removal with common tools, improving assembly efficiency.
• Full threading ensures consistent clamping force along the entire length, ideal for demanding mechanical assemblies.
• Compliance with major standards including ASME B18.3 and ASTM A574, assuring quality and interoperability in professional settings.

Professional Applications & Engineering Value

This 5/16"-18 UNC Socket Head Cap Screw is engineered to address critical challenges in heavy-duty industrial applications. The zinc-flake-coated alloy steel construction provides robust corrosion resistance, making it suitable for environments exposed to moisture, chemicals, or outdoor elements. Its coarse UNC thread and Class 3A fit deliver superior holding power and vibration resistance, preventing joint failure in machinery, automotive assemblies, and structural frameworks. The fully threaded, right-hand design ensures uniform stress distribution, while the 1/4" hex drive facilitates quick installation in confined spaces. Ideal for high-strength fastening in construction, manufacturing, and equipment maintenance, this screw combines durability with compliance to streamline procurement and enhance operational reliability.

Specification Summary & Compliance

This socket head cap screw features a 5/16"-18 UNC coarse thread with a Class 3A thread fit for precise dimensional accuracy. It adheres to ASME B18.3 and ASTM A574 manufacturing specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in global industrial markets.