S-91274A160 1/4"-20 x 5/8" 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 from the zinc-flake coating protects against rust and extends service life in harsh industrial environments.
• Precise Class 3A thread fit provides secure, vibration-resistant connections, minimizing loosening in dynamic assemblies.
• High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• Hex socket drive design allows for easy installation in confined spaces with standard tools, improving assembly efficiency.
• Full threading ensures consistent engagement along the entire length, providing uniform clamping force.
• Compliance with ASME B18.3 and ASTM A574 guarantees consistent quality and interchangeability in professional applications.

Professional Applications & Engineering Value

This 1/4"-20 UNC Socket Head Cap Screw is engineered to address critical challenges in industrial assembly where reliability and durability are paramount. The zinc-flake-coated alloy steel construction provides robust protection against corrosion, making it ideal for machinery, automotive, and outdoor equipment exposed to moisture or chemicals. The coarse UNC thread and Class 3A fit deliver superior resistance to vibration loosening, ensuring stable performance in high-load environments. With its hex drive socket head, it facilitates quick installation in tight spaces, reducing assembly time and labor costs. This fastener is particularly valuable in applications requiring high tensile strength and long-term reliability, such as heavy-duty frames, engine components, and precision instruments.

Specification Summary & Compliance

This product features a 1/4"-20 UNC thread with Class 3A fit and coarse thread spacing, ensuring precise dimensional accuracy per ASME B18.3 and material specifications per ASTM A574. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental standards. The manufacturing process adheres to rigorous quality controls, providing consistent performance for industrial use.