S-94705A811 1 1/8"-8 x 3 1/4" 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 mechanical loads, reducing the risk of fastener failure in critical applications.
• High hardness rating (Rockwell C35) provides superior resistance to wear and deformation, extending service life in high-stress environments.
• Fine UN threading with Class 2A fit offers precise, secure engagement for vibration resistance and improved clamping force in assembled components.
• Fully threaded design allows for maximum grip length and uniform stress distribution, enhancing joint integrity across varied material thicknesses.
• External hex drive and large head dimensions (1 13/16" width) enable easy installation and high torque application with standard tools, speeding up assembly processes.
• ASTM A193 Grade B7 compliance guarantees material quality and consistency, meeting rigorous industrial standards for high-temperature and high-pressure services.
• Right-hand thread direction ensures compatibility with standard installation practices, minimizing errors and improving workflow efficiency.

Professional Applications & Engineering Value

This 1 1/8"-8 hex head screw is engineered to address common industrial challenges such as joint loosening under dynamic loads and corrosion in harsh operating conditions. Manufactured from ASTM Grade B7 steel, it delivers high tensile strength and thermal stability, making it ideal for pressure vessels, valve assemblies, and structural fastening in oil & gas, power generation, and heavy machinery sectors. The UN fine thread configuration ensures tight sealing and superior fatigue resistance, while the fully threaded body accommodates varying clamp lengths without compromising strength. By combining 125,000 PSI tensile capability with precise Class 2A thread fit, this fastener minimizes maintenance downtime and enhances safety in critical bolted connections.

Specification Summary & Compliance

This product adheres to inch system measurements with a thread size of 1 1/8"-8 and Class 2A thread fit for consistent dimensional accuracy. It conforms to ASTM A193 Grade B7 specifications, ensuring material traceability and performance reliability. The screw features fully threaded UN fine threads, right-hand direction, and meets industry standards for high-strength applications. Compliance with relevant regulations, including material and manufacturing guidelines, is maintained for industrial use.