S-94705A785 7/8"-9 x 5 3/4" ASTM A193 Steel Heavy Hex Head Screws for High-Pressure Applications

Key Features & Benefits at a Glance

• Exceptional tensile strength of 125,000 psi ensures reliable performance under extreme loads, minimizing the risk of fastener failure in critical applications.
• High hardness rating (Rockwell C35) provides superior resistance to wear and deformation, extending the service life of the screw in demanding environments.
• Coarse UNC threading offers faster installation and superior resistance to vibration loosening compared to fine threads, ideal for heavy machinery and structural assemblies.
• Class 2A thread fit guarantees consistent, free-spinning assembly with standard nuts, reducing installation time and preventing cross-threading issues.
• ASTM A193 Grade B7 material specification ensures the screw meets rigorous chemical and mechanical property standards for high-temperature and high-pressure service.
• Partially threaded design with a defined grip length provides concentrated clamping force on the joint, enhancing connection stability.
• External hex drive and large head width (1 7/16") allow for high torque application with standard tools, ensuring a secure and tight fastening.

Professional Applications & Engineering Value

Engineered for high-stress industrial applications, this Grade B7 steel hex head screw delivers outstanding performance in pressure vessel systems, valve assemblies, and structural steel connections. Its coarse UNC thread and Class 2A fit enable quick, reliable assembly even in environments with vibration, reducing maintenance downtime. The ASTM A193 compliance and 125,000 psi tensile strength make it a trusted choice for engineers specifying components for elevated temperature and high-pressure services, where material integrity and fastener durability are non-negotiable. The partially threaded shank ensures that the full clamping force is applied directly to the joint, preventing loosening and maintaining seal integrity in flanged connections.

Specification Summary & Compliance

This screw adheres to inch system measurements with a Class 2A thread fit for consistent assembly. It conforms to UNC coarse thread standards (7/8"-9) and is manufactured in compliance with the ASTM A193 specification for high-temperature service. The material, ASTM Grade B7 steel, meets defined requirements for chemical composition and mechanical properties, ensuring reliability in demanding industrial environments.