S-91251A016 1/2"-20 x 1 1/2" 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.
• Class 3A thread fit provides superior precision and tight tolerances for secure, vibration-resistant assemblies in critical machinery.
• Black-oxide coating on alloy steel offers enhanced corrosion resistance and durability, extending service life in harsh industrial environments.
• Fine thread spacing (UNF) delivers improved clamping force and better load distribution, ideal for precision engineering components.
• Fully threaded design allows for consistent engagement along the entire length, facilitating easy adjustment and strong holding power.
• 3/8" hex drive socket head enables efficient installation with standard tools, minimizing assembly time and labor costs.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material quality and environmental safety, meeting global regulatory standards for industrial use.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address common challenges in demanding sectors such as automotive, aerospace, and heavy machinery. The 1/2"-20 UNF fine thread and Class 3A fit provide exceptional accuracy, reducing the likelihood of loosening under vibration and dynamic loads. Made from high-strength alloy steel with a Rockwell C37 hardness, it withstands extreme pressures and repetitive stress, making it ideal for critical joints and precision assemblies. The black-oxide surface treatment not only resists corrosion but also minimizes galling, ensuring smooth installation and long-term reliability in harsh conditions. By integrating these features, this fastener enhances assembly integrity, reduces maintenance needs, and supports efficient production workflows.

Specification Summary & Compliance

This socket head cap screw adheres to precise dimensional standards, including Class 3A thread fit for tight tolerances and UNF fine thread spacing. It meets ASTM A574 specifications for high-strength alloy steel fasteners, ensuring consistent quality and performance. Additionally, the product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental responsibility for industrial applications.