S-91274A328 3/8"-16 x 2 1/4" 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 under high-stress conditions, reducing the risk of fastener failure in critical assemblies.
• Superior corrosion resistance from the zinc-flake coating protects against rust and environmental degradation, extending service life in harsh industrial settings.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant connections, minimizing loosening in dynamic applications.
• High hardness (Rockwell C37) offers excellent wear resistance and durability, maintaining thread integrity through repeated use and high torque.
• Hex socket drive design allows for easy installation and removal with standard tools, improving assembly efficiency and reducing labor time.
• Compliance with ASME B18.3 and ASTM A574 guarantees consistent quality and interchangeability, meeting rigorous engineering standards for industrial use.
• RoHS 3 and REACH compliance ensures environmental safety and regulatory adherence, making them suitable for global supply chains and eco-conscious projects.

Professional Applications & Engineering Value

Engineered for demanding environments, these Socket Head Cap Screws combine zinc-flake-coated alloy steel with a Class 3A UNC coarse thread to address common industrial challenges like vibration-induced loosening and corrosion. The partially threaded design with a minimum thread length of 1 1/4" ensures optimal grip in materials prone to stress concentration, while the hex drive facilitates quick installation in confined spaces. Ideal for machinery, automotive, and heavy equipment applications, they deliver high tensile strength and durability, reducing maintenance needs and downtime. The coating and material selection provide long-term reliability, making them a cost-effective solution for high-strength fastening in corrosive or high-load scenarios.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including a Class 3A thread fit and UNC coarse thread spacing for consistent engagement. It meets ASME B18.3 and ASTM A574 specifications, ensuring manufacturing quality and performance reliability. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), it supports environmental and safety regulations, with additional validation from ASTM B117 for corrosion resistance.