S-91251A520 3/4"-10 x 1 3/8" 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 fit with Class 3A tolerance provides precise engagement and vibration resistance, maintaining joint integrity in machinery and equipment.
• Black-oxide surface treatment on alloy steel offers enhanced corrosion resistance, extending service life in industrial environments.
• High hardness (Rockwell C37) increases wear resistance, ensuring durability and repeated usability without deformation.
• 5/8" hex drive and standard socket head allow for easy installation and high torque application, improving assembly efficiency.
• Coarse UNC threads enable quick assembly and disassembly, saving time in maintenance and production workflows.
• Full threading along the 1 3/8" length provides consistent clamping force and versatility in various material thicknesses.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in industrial settings, such as vibration loosening and corrosion-induced degradation. The alloy steel construction combined with a black-oxide finish resists environmental factors, making it ideal for heavy machinery, automotive assemblies, and construction equipment where exposure to moisture and chemicals is common. The 3/4"-10 UNC coarse thread and Class 3A fit ensure secure fastening in high-vibration applications, minimizing maintenance downtime. Its high tensile strength and Rockwell C37 hardness provide reliable performance in structural and load-bearing components, supporting operational safety and longevity in industrial fastening systems.

Specification Summary & Compliance

This socket head cap screw features precise Class 3A thread fit and UNC coarse threads with a diameter of 0.75" and length of 1 3/8". It is manufactured in accordance with ASTM A574 specifications and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material quality for global industrial use.