S-91251A155 6-32 x 1 1/4" ASTM A574 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 demanding applications.
• Superior corrosion resistance from the black-oxide finish prolongs service life and maintains integrity in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• Hex socket drive design allows for high torque application and easy installation in confined spaces, improving assembly efficiency.
• Partially threaded shank offers optimal grip and clamping force control, ideal for components requiring precise positioning.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency and environmental safety, meeting global regulatory standards.
• Coarse UNC threading enables quick engagement and reduced cross-threading risk, speeding up production cycles.

Professional Applications & Engineering Value

Engineered for industrial fastening challenges, these socket head cap screws combine black-oxide alloy steel with a Class 3A UNC thread to address common issues like vibration-induced loosening and corrosion. The high tensile strength and Rockwell C37 hardness ensure durability in heavy machinery, automotive assemblies, and precision equipment, where consistent clamp load is critical. The hex drive and standard socket head profile facilitate secure tool engagement, reducing strip-out risks and maintenance downtime. This design is optimal for applications requiring reliable, repeatable fastening without compromising on environmental compliance or long-term performance.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit for precise dimensional accuracy under UNC coarse thread standards, with a minimum thread length of 3/4" on a partially threaded rod. Manufacturing follows ASTM A574 specifications, ensuring material integrity and performance. It is fully RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, supporting safe and sustainable use in regulated industries.