S-91251A473 3/8"-24 x 3 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 under high-stress conditions, reducing the risk of fastener failure in critical applications.
• Superior thread precision with Class 3A fit provides tighter tolerances and improved fatigue resistance for secure, vibration-resistant assemblies.
• Black-oxide surface treatment on alloy steel offers enhanced corrosion resistance and a sleek appearance without compromising dimensional integrity.
• Partially threaded design allows for precise clamping force control, minimizing thread damage and simplifying alignment in assembled components.
• Fine UNRF threads deliver better load distribution and sealing capabilities compared to coarse threads, ideal for precision machinery and equipment.
• 5/16" hex drive socket enables high-torque installation with standard tools, facilitating efficient assembly and maintenance in confined spaces.
• Rockwell C37 hardness balances durability and machinability, ensuring long service life without brittleness in dynamic industrial environments.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address common challenges in high-performance assemblies, such as vibration loosening and corrosion-induced degradation. The fine UNRF thread and Class 3A fit provide exceptional clamping force retention, making it ideal for precision equipment, automotive systems, and heavy machinery where reliability is paramount. The partially threaded shank reduces stress concentration points, while the alloy steel construction with 170,000 psi tensile strength ensures durability under cyclic loads. Its black-oxide finish not only resists environmental factors but also maintains consistent torque values, streamlining installation in aerospace, manufacturing, and robotics applications that demand exacting standards.

Specification Summary & Compliance

This socket head cap screw features a 3/8"-24 UNRF fine thread with Class 3A thread fit for high precision, and a length of 3-1/2" with a minimum thread length of 1-1/4". It complies with ASTM A574 specifications for high-strength metric and inch socket head cap screws, ensuring consistent manufacturing quality. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.