S-91251A335 3/8"-16 x 1 7/8" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 PSI ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel extends service life in harsh industrial environments.
• Precise Class 3A thread fit guarantees tight, secure connections with minimal backlash, enhancing assembly accuracy.
• Hex socket drive design allows for high-torque installation and removal, ideal for confined spaces and repetitive use.
• Coarse UNC threads provide faster installation and better resistance to vibration loosening compared to fine threads.
• Partially threaded shank offers optimal grip and clamping force where full threading isn't required, improving joint integrity.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency, environmental safety, and global regulatory acceptance.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these socket head cap screws deliver robust performance in machinery, automotive assemblies, and heavy equipment. The black-oxide alloy steel construction combats rust and wear, while the 3/8"-16 UNC coarse threads with Class 3A fit provide superior engagement and vibration resistance. The hex drive and partially threaded design enable efficient installation in tight spaces, reducing assembly time and maintenance costs. Ideal for high-stress environments, these screws ensure long-term reliability and compliance with ASTM A574 standards, making them a trusted choice for engineers seeking durability and precision.

Specification Summary & Compliance

This socket head cap screw features a 3/8"-16 UNC thread with Class 3A precision fit, ensuring tight tolerances and reliable performance. Manufactured to ASTM A574 specifications, it meets stringent quality standards for high-strength fasteners. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), supporting environmental and safety regulations. With a Rockwell C37 hardness and 170,000 PSI tensile strength, it is designed for rigorous industrial use, offering consistent durability and mechanical integrity.