S-91251A033 1/2"-20 x 6" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Superior tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Exceptional hardness at Rockwell C37 provides excellent wear resistance and durability for long service life in demanding environments.
• Precision Class 3A thread fit guarantees tight, secure connections with minimal backlash, enhancing assembly accuracy and reliability.
• Black-oxide coating on alloy steel offers corrosion resistance and a clean, professional appearance without compromising dimensional integrity.
• Partially threaded design allows for controlled clamping force and easier alignment in specific assembly scenarios.
• Fine UNRF thread delivers improved vibration resistance and finer adjustment capabilities compared to coarse threads.
• Hex socket drive enables high-torque installation with standard tools, reducing stripping and improving installation efficiency.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in industrial and mechanical assemblies. The 1/2"-20 UNRF fine thread and Class 3A thread fit provide superior resistance to loosening under vibration, making it ideal for machinery, automotive, and heavy equipment applications. The partially threaded configuration ensures precise clamping where full threading isn't required, reducing stress concentration. With a 170,000 psi tensile strength and Rockwell C37 hardness, it withstands extreme loads and repetitive use, minimizing maintenance downtime. The black-oxide surface treatment adds a layer of corrosion protection without altering thread dimensions, ensuring consistent performance in harsh environments. These features collectively enhance reliability in high-strength fastening systems, supporting efficient production and long-term operational stability.

Specification Summary & Compliance

This socket head cap screw features a 1/2"-20 UNRF fine thread with Class 3A thread fit for precise dimensional accuracy and tight tolerances. It is manufactured in accordance with ASTM A574 specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its adherence to environmental and safety standards for industrial use.