S-91251A371 5/16"-24 x 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 thread precision with Class 3A fit provides tighter tolerances and improved fatigue resistance, minimizing loosening and vibration-related issues.
• Durable black-oxide coating on alloy steel offers enhanced corrosion resistance and a sleek appearance, extending service life in various industrial environments.
• Partially threaded design allows for precise clamping force control and secure fastening in assemblies requiring specific unthreaded shank sections.
• Fine thread spacing (UNF) delivers better adjustment accuracy and higher load distribution compared to coarse threads, ideal for precision equipment.
• High hardness (Rockwell C37) ensures excellent wear resistance and durability, maintaining structural integrity through repeated use and high-torque applications.
• Compliance with ASTM A574 guarantees consistent quality and performance, meeting rigorous industry standards for socket head cap screws.

Professional Applications & Engineering Value

These 5/16"-24 UNF socket head cap screws are engineered to address critical challenges in industrial settings, such as vibration-induced loosening and material fatigue. The black-oxide alloy steel construction provides robust corrosion resistance, making them suitable for machinery, automotive, and aerospace applications where exposure to harsh conditions is common. The fine thread spacing and Class 3A thread fit ensure secure, precise fastening in high-precision assemblies, reducing maintenance needs and enhancing operational reliability. With a partially threaded design, they offer optimal grip and alignment in components requiring specific clamping zones, delivering long-term performance and cost savings by minimizing downtime and replacement frequency.

Specification Summary & Compliance

This product adheres to Class 3A thread fit for precise dimensional accuracy and UNF fine thread standards with a size of 5/16"-24. It meets ASTM A574 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity for global industrial use.