S-91251A811 5/8"-11 x 4 1/4" 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 thread precision with Class 3A fit provides secure, vibration-resistant connections, minimizing loosening in dynamic environments.
• Durable black-oxide coating on alloy steel offers enhanced corrosion resistance, extending service life in harsh industrial conditions.
• High hardness rating (Rockwell C37) maintains structural integrity under heavy loads, preventing deformation and wear.
• Coarse UNRC threads enable quick and easy installation, saving time and labor in assembly processes.
• Partially threaded design allows for precise clamping force control, ideal for applications requiring specific grip lengths.
• Compliance with ASTM A574 guarantees consistent quality and performance, meeting rigorous industry standards for socket head cap screws.

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws are engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, automotive systems, and construction equipment. The Class 3A thread fit and coarse UNRC threads ensure tight, reliable fastening even under vibration and dynamic loads, reducing maintenance needs. With a Rockwell C37 hardness and 170,000 psi tensile strength, they resist stripping and shearing in high-torque applications. The black-oxide surface treatment provides an added layer of corrosion protection, making them suitable for environments exposed to moisture or chemicals. Their partially threaded configuration offers flexibility in securing components without over-tightening, enhancing safety and longevity in precision engineering projects.

Specification Summary & Compliance

This socket head cap screw features a 5/8"-11 UNRC coarse thread with a Class 3A thread fit for high precision and minimal tolerance deviations. It meets ASTM A574 specifications for material and manufacturing consistency, ensuring reliable performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in various industrial applications without hazardous substances.