S-91251A122 1/2"-13 x 8 1/2" 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, extending service life in demanding industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant connections in machinery and equipment.
• 3/8" hex drive design allows for high-torque installation with standard tools, speeding up assembly and maintenance processes.
• Partially threaded shank offers optimal grip and clamping force where needed, enhancing joint integrity in structural applications.
• Compliance with ASTM A574 guarantees consistent quality and mechanical properties, ensuring reliability for critical B2B uses.
• RoHS 3 and REACH compliance supports environmental and safety standards, making it suitable for global supply chains.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges, such as vibration loosening and corrosion in heavy machinery. The coarse UNRC thread and Class 3A fit ensure quick, secure fastening in materials like steel and cast iron, minimizing assembly time while maintaining high clamp load. With a Rockwell C37 hardness and robust 1/2"-13 thread size, it withstands dynamic loads in applications like automotive frames, construction equipment, and manufacturing tools. The partially threaded design concentrates stress effectively, reducing the risk of strip-out and enhancing durability in repetitive use scenarios, making it a cost-effective solution for B2B procurement.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit for precise dimensional accuracy under the inch system, with a coarse UNRC thread type and 1/2"-13 thread size. It meets ASTM A574 specifications for high-strength fasteners, ensuring consistent performance. Compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming it is free from hazardous substances for industrial and international use.