S-91251A698 9/16"-18 x 1 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 under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior thread precision with Class 3A fit provides tight, secure fastening with minimal play, enhancing assembly accuracy and vibration resistance.
• Durable black-oxide coating on alloy steel offers excellent corrosion resistance and a sleek finish, extending service life in harsh industrial environments.
• Fine UNF thread design (18 TPI) allows for finer adjustments and improved load distribution compared to coarse threads, ideal for precision machinery.
• Fully threaded shank enables consistent engagement along the entire length, providing uniform clamping force and flexibility in various mounting depths.
• Standard hex socket drive (7/16") facilitates easy installation with common tools, reducing assembly time and minimizing strip-out risks.
• Compliance with ASTM A574, RoHS 3, and REACH standards ensures material quality, environmental safety, and suitability for regulated industries.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in industrial settings, such as vibration-induced loosening and corrosion in high-stress assemblies. The UNF fine thread (9/16"-18) provides enhanced grip and precise tension control, making it ideal for applications in precision machinery, automotive systems, and heavy equipment where reliability is paramount. The Class 3A thread fit ensures minimal tolerance deviations, reducing the need for rework and improving overall assembly efficiency. Combined with a Rockwell C37 hardness and robust alloy steel construction, it withstands repetitive loads and harsh conditions, delivering long-term performance while meeting stringent ASTM A574 specifications for consistency and durability.

Specification Summary & Compliance

This socket head cap screw features a Class 3A thread fit with precise dimensional accuracy per UNF standards, ensuring reliable engagement. It adheres to ASTM A574 manufacturing specifications for high-strength alloy steel fasteners and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and regulated industrial applications.