S-91251A881 7/8"-9 x 2 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 corrosion resistance from the black-oxide finish extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides secure, vibration-resistant connections, enhancing assembly integrity and safety.
• High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• Coarse UNRC threads allow for quicker installation and reduced cross-threading risks, saving time in assembly lines.
• Fully threaded design ensures consistent clamping force along the entire length, ideal for adjustable or deep-set applications.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety, meeting global industry standards.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, automotive systems, and construction equipment. The alloy steel material combined with a black-oxide surface treatment provides robust protection against corrosion and abrasion, solving common issues like fastener degradation in humid or chemically exposed environments. Its coarse UNRC threads and Class 3A fit ensure quick, secure fastening even in high-vibration applications, reducing downtime and improving operational efficiency. With a hex drive design and standardized socket head profile, it enables easy installation in confined spaces, making it a reliable choice for engineers seeking durability and compliance with ASTM A574 specifications.

Specification Summary & Compliance

This socket head cap screw features precise Class 3A thread fit per UNRC coarse thread standards, with a thread size of 7/8"-9 and full threading for consistent performance. It adheres to ASTM A574 manufacturing specifications, ensuring high strength and dimensional accuracy. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in regulated industries without hazardous substances.