S-91251A339 3/8"-24 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 precision with Class 3A fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening in critical machinery.
• Durable black-oxide finish on alloy steel offers enhanced corrosion resistance, extending service life in harsh industrial environments.
• High hardness rating (Rockwell C37) maintains structural integrity and wear resistance, ideal for repetitive use and heavy-duty fastening.
• Fine UNF threads (3/8"-24) deliver improved clamping force and finer adjustment control compared to coarse threads, perfect for precision equipment.
• Fully threaded design allows for consistent engagement along the entire length, providing uniform load distribution and versatile installation options.
• Hex socket drive (5/16") enables high-torque application with standard tools, facilitating quick and secure assembly in confined spaces.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration-induced loosening and corrosion in machinery. The Class 3A thread fit and fine UNF threads ensure precise, secure fastening in high-precision assemblies like automotive engines, aerospace components, and heavy equipment. The 170,000 PSI tensile strength and Rockwell C37 hardness provide reliable performance under extreme loads, reducing maintenance needs and downtime. Its fully threaded configuration offers flexibility in adjustment, while the black-oxide surface treatment enhances durability against moisture and chemicals, making it suitable for OEM and MRO applications where longevity and compliance are critical.

Specification Summary & Compliance

This socket head cap screw features a 3/8"-24 UNF fine thread with Class 3A fit for high precision and dimensional accuracy. It meets ASTM A574 specifications for alloy steel socket head cap screws, ensuring consistent manufacturing quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe industrial use.